qid int64 1 74.7M | question stringlengths 12 33.8k | date stringlengths 10 10 | metadata list | response_j stringlengths 0 115k | response_k stringlengths 2 98.3k |
|---|---|---|---|---|---|
224,521 | *[Blindsight](https://en.wikipedia.org/wiki/Blindsight_(Watts_novel))* mentions a group of 5 transhumans in a first contact with an unconscious alien species (Rorschach).
Which the writer mentions any form of communication in human language, interpreted by the species is treated as an attack. But how?
From the book:
>
> "Since Rorschach doesn’t have consciousness, human languages and signals are meaningless to it. The act of receiving and decoding the signals consumes time and energy but yield no benefit for Rorschach. Thus, for Rorschach, human language is virus, and “communication” in human language is an attack.
>
>
> "Imagine that you encounter a signal. It is structured, and dense with information. It meets all the criteria of an intelligent transmission. Evolution and experience offer a variety of paths to follow, branch-points in the flowcharts that handle such input.
>
>
> There are no meaningful translations for these terms. They are needlessly recursive. They contain no usable intelligence, yet they are structured intelligently; there is no chance they could have arisen by chance. The only explanation is that something has coded nonsense in a way that poses as a useful message; only after wasting time and effort does the deception becomes apparent. The signal functions to consume the resources of a recipient for zero payoff and reduced fitness. The signal is a virus. Viruses do not arise from kin, symbionts, or other allies. The signal is an attack."
>
>
>
The writing is quite dense and could anyone explains whats the reasoning behind human language being hostile when interpreted by the Rorschach? | 2019/12/17 | [
"https://scifi.stackexchange.com/questions/224521",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/124225/"
] | It looks like you're asking for an interpretation of this passage from the book.
The key point, is that Rorschach has *assigned a motive* to the communication. Since it cannot interpret the message, it can only suppose that the message *has* no meaning; it has categorized the message as nonsense, and furthermore categorized it as *deliberate* nonsense. It's as if it's thinking "Why else would something communicate a message with no meaning? It must be on purpose!" Since attempting to interpret the message consumes energy, Rorschach views the communication as ethically equivalent to trying to suffocate it to death with a pillow. This may not be what the transhumans intended, but no other interpretation has occurred to Rorschach, so it takes it as an attack. | It's not *all* human language that is interpreted as an attack, it's specifically inter-human messages that *assume consciousness*. Since Rorschach is non-conscious, it doesn't have the terms of reference available to 'understand' those messages.
There are examples given, between the passages you quote. In my 2006 Tor edition, the relevant section starts on p.323 with "Imagine you're a scrambler"
>
> You decode the [intercepted human-to-human] signals, and stumble:
>
>
> *I **had a great time**. I **really enjoyed** him. Even if he cost twice as much as any other hooker in the dome--*
>
>
> *To **fully appreciate** Kesey's Quartet--*
>
>
> *They **hate** us for our freedom--*
>
>
> ***Pay attention**, now--*
>
>
> ***Understand**.*
>
>
>
My emphases indicate the particular parts that would *have no meaning* to a non-conscious intelligence.
You can see the kind of non-conscious language that would *not* be interpreted as an attack, later on after
>
> vampires take over the Earth, and all the humans are killed - the comms Siri picks up from his escape torpedo are "mostly traffic control and telemetry", but "Every now and then I still hear a burst of pure voice, tight with tension ... other ships in **dispassionate** pursuit" - vampires, who as it turns out are also non-conscious, chasing down the last humans.
>
>
> |
224,521 | *[Blindsight](https://en.wikipedia.org/wiki/Blindsight_(Watts_novel))* mentions a group of 5 transhumans in a first contact with an unconscious alien species (Rorschach).
Which the writer mentions any form of communication in human language, interpreted by the species is treated as an attack. But how?
From the book:
>
> "Since Rorschach doesn’t have consciousness, human languages and signals are meaningless to it. The act of receiving and decoding the signals consumes time and energy but yield no benefit for Rorschach. Thus, for Rorschach, human language is virus, and “communication” in human language is an attack.
>
>
> "Imagine that you encounter a signal. It is structured, and dense with information. It meets all the criteria of an intelligent transmission. Evolution and experience offer a variety of paths to follow, branch-points in the flowcharts that handle such input.
>
>
> There are no meaningful translations for these terms. They are needlessly recursive. They contain no usable intelligence, yet they are structured intelligently; there is no chance they could have arisen by chance. The only explanation is that something has coded nonsense in a way that poses as a useful message; only after wasting time and effort does the deception becomes apparent. The signal functions to consume the resources of a recipient for zero payoff and reduced fitness. The signal is a virus. Viruses do not arise from kin, symbionts, or other allies. The signal is an attack."
>
>
>
The writing is quite dense and could anyone explains whats the reasoning behind human language being hostile when interpreted by the Rorschach? | 2019/12/17 | [
"https://scifi.stackexchange.com/questions/224521",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/124225/"
] | I think a real world example of this would be a DDOS attack on a website. Malicious users flood the website with, more-or-less, nonsense signals. This takes up all the website's ability to interpret any sort of incoming information. If someone watching the website notices a bunch of nonsense signals hitting the site, they could assume it was an attack on the site.
So the Rorschach species might interpret the nonsense communications similarly as a malicious attack. | It looks like you're asking for an interpretation of this passage from the book.
The key point, is that Rorschach has *assigned a motive* to the communication. Since it cannot interpret the message, it can only suppose that the message *has* no meaning; it has categorized the message as nonsense, and furthermore categorized it as *deliberate* nonsense. It's as if it's thinking "Why else would something communicate a message with no meaning? It must be on purpose!" Since attempting to interpret the message consumes energy, Rorschach views the communication as ethically equivalent to trying to suffocate it to death with a pillow. This may not be what the transhumans intended, but no other interpretation has occurred to Rorschach, so it takes it as an attack. |
224,521 | *[Blindsight](https://en.wikipedia.org/wiki/Blindsight_(Watts_novel))* mentions a group of 5 transhumans in a first contact with an unconscious alien species (Rorschach).
Which the writer mentions any form of communication in human language, interpreted by the species is treated as an attack. But how?
From the book:
>
> "Since Rorschach doesn’t have consciousness, human languages and signals are meaningless to it. The act of receiving and decoding the signals consumes time and energy but yield no benefit for Rorschach. Thus, for Rorschach, human language is virus, and “communication” in human language is an attack.
>
>
> "Imagine that you encounter a signal. It is structured, and dense with information. It meets all the criteria of an intelligent transmission. Evolution and experience offer a variety of paths to follow, branch-points in the flowcharts that handle such input.
>
>
> There are no meaningful translations for these terms. They are needlessly recursive. They contain no usable intelligence, yet they are structured intelligently; there is no chance they could have arisen by chance. The only explanation is that something has coded nonsense in a way that poses as a useful message; only after wasting time and effort does the deception becomes apparent. The signal functions to consume the resources of a recipient for zero payoff and reduced fitness. The signal is a virus. Viruses do not arise from kin, symbionts, or other allies. The signal is an attack."
>
>
>
The writing is quite dense and could anyone explains whats the reasoning behind human language being hostile when interpreted by the Rorschach? | 2019/12/17 | [
"https://scifi.stackexchange.com/questions/224521",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/124225/"
] | Rorschach is not conscious, which means that it does not spend energy on daydreaming, on emotion, on opinions, or on any part of what we would experience as consciously processing our experiences. This means that to a species like Rorschach, a large part - in fact, the vast majority - of communication between humans is concerning activities that it has no purpose for, and cannot comprehend the need for.
Rorschach only spends energy on things that are directly related to its continued survival. Human activities such as entertainment are therefore considered a complete waste of energy. Even the structure of human language is wasteful - I seem to remember there being a line describing how Rorschach units "time-share" each other's brains. What this means is that Rorschach units don't "speak"; they simply transmit their thoughts in whatever form is more efficient (if I remember correctly, the trapped Rorschach entities communicated by transmitting vibrations through the hull) and each unit continues thinking the recieved thought where the original left off; a true hive-mind, essentially one brain spread across many bodies. Imagine that's how you communicate, then look at the way humans do it: by inventing words with certain meanings, choosing which ones you want to use to express an idea, and then representing those thoughts by a means of sound that includes tonality and stress patterns and tempo, which are all there to indicate social, emotional, and contextual cues... It's tremendously inefficient, from Rorschach's point of view.
When Rorschach encounters this communication, it has to analyse it and work out what it is. Doing so requires understanding all the things I just mentioned, and when it does that, it sees that so much of it is (from Rorschach's perspective) completely unneeded and wasteful. This means that the communication has made Rorschach spend energy on doing something that was ultimately not in any way useful in ensuring its continued survival. Rorschach does not have an unlimited energy budget, which means that by spending some of its energy on understanding human communication, Rorschach is now less able to pursue the activities that it needs to in order to survive.
This means that there is an intelligent creature out there that has done something that has reduced Rorschach's ability to survive. From Rorschach's single-minded perspective, this counts as an attack. The creature who is doing this must be stopped, so that Rorschach no longer has to spend energy on dealing with it, and can instead focus entirely on making its environment safer for Rorschach to live in and ensuring the continuation of its species.
I've tried to phrase this in a way that doesn't imply that Rorschach has opinions or conscious thought; in essence, Rorschach operates solely by what humans would call instinct, reflex, and gut reaction, except vastly more complex; much more direct cause-and-effect and much less reasoning and rationalisation. That's part of what makes Rorschach so scary: it cannot be reasoned with, because it lacks the capability to even think the sort of thoughts that would be required for it to engage in negotiation of the human kind. It cannot be reassured or intimidated, because it is incapable of experiencing fear or concern. The only "negotiation" it would understand is based on actions; humans would have to act in a way that led Rorschach to decide that they are not a threat. Given that this would involve ensuring that Rorschach no longer has to expend any energy in thinking about or reacting to human activities, this is very unlikely. | It looks like you're asking for an interpretation of this passage from the book.
The key point, is that Rorschach has *assigned a motive* to the communication. Since it cannot interpret the message, it can only suppose that the message *has* no meaning; it has categorized the message as nonsense, and furthermore categorized it as *deliberate* nonsense. It's as if it's thinking "Why else would something communicate a message with no meaning? It must be on purpose!" Since attempting to interpret the message consumes energy, Rorschach views the communication as ethically equivalent to trying to suffocate it to death with a pillow. This may not be what the transhumans intended, but no other interpretation has occurred to Rorschach, so it takes it as an attack. |
224,521 | *[Blindsight](https://en.wikipedia.org/wiki/Blindsight_(Watts_novel))* mentions a group of 5 transhumans in a first contact with an unconscious alien species (Rorschach).
Which the writer mentions any form of communication in human language, interpreted by the species is treated as an attack. But how?
From the book:
>
> "Since Rorschach doesn’t have consciousness, human languages and signals are meaningless to it. The act of receiving and decoding the signals consumes time and energy but yield no benefit for Rorschach. Thus, for Rorschach, human language is virus, and “communication” in human language is an attack.
>
>
> "Imagine that you encounter a signal. It is structured, and dense with information. It meets all the criteria of an intelligent transmission. Evolution and experience offer a variety of paths to follow, branch-points in the flowcharts that handle such input.
>
>
> There are no meaningful translations for these terms. They are needlessly recursive. They contain no usable intelligence, yet they are structured intelligently; there is no chance they could have arisen by chance. The only explanation is that something has coded nonsense in a way that poses as a useful message; only after wasting time and effort does the deception becomes apparent. The signal functions to consume the resources of a recipient for zero payoff and reduced fitness. The signal is a virus. Viruses do not arise from kin, symbionts, or other allies. The signal is an attack."
>
>
>
The writing is quite dense and could anyone explains whats the reasoning behind human language being hostile when interpreted by the Rorschach? | 2019/12/17 | [
"https://scifi.stackexchange.com/questions/224521",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/124225/"
] | I think a real world example of this would be a DDOS attack on a website. Malicious users flood the website with, more-or-less, nonsense signals. This takes up all the website's ability to interpret any sort of incoming information. If someone watching the website notices a bunch of nonsense signals hitting the site, they could assume it was an attack on the site.
So the Rorschach species might interpret the nonsense communications similarly as a malicious attack. | It's not *all* human language that is interpreted as an attack, it's specifically inter-human messages that *assume consciousness*. Since Rorschach is non-conscious, it doesn't have the terms of reference available to 'understand' those messages.
There are examples given, between the passages you quote. In my 2006 Tor edition, the relevant section starts on p.323 with "Imagine you're a scrambler"
>
> You decode the [intercepted human-to-human] signals, and stumble:
>
>
> *I **had a great time**. I **really enjoyed** him. Even if he cost twice as much as any other hooker in the dome--*
>
>
> *To **fully appreciate** Kesey's Quartet--*
>
>
> *They **hate** us for our freedom--*
>
>
> ***Pay attention**, now--*
>
>
> ***Understand**.*
>
>
>
My emphases indicate the particular parts that would *have no meaning* to a non-conscious intelligence.
You can see the kind of non-conscious language that would *not* be interpreted as an attack, later on after
>
> vampires take over the Earth, and all the humans are killed - the comms Siri picks up from his escape torpedo are "mostly traffic control and telemetry", but "Every now and then I still hear a burst of pure voice, tight with tension ... other ships in **dispassionate** pursuit" - vampires, who as it turns out are also non-conscious, chasing down the last humans.
>
>
> |
224,521 | *[Blindsight](https://en.wikipedia.org/wiki/Blindsight_(Watts_novel))* mentions a group of 5 transhumans in a first contact with an unconscious alien species (Rorschach).
Which the writer mentions any form of communication in human language, interpreted by the species is treated as an attack. But how?
From the book:
>
> "Since Rorschach doesn’t have consciousness, human languages and signals are meaningless to it. The act of receiving and decoding the signals consumes time and energy but yield no benefit for Rorschach. Thus, for Rorschach, human language is virus, and “communication” in human language is an attack.
>
>
> "Imagine that you encounter a signal. It is structured, and dense with information. It meets all the criteria of an intelligent transmission. Evolution and experience offer a variety of paths to follow, branch-points in the flowcharts that handle such input.
>
>
> There are no meaningful translations for these terms. They are needlessly recursive. They contain no usable intelligence, yet they are structured intelligently; there is no chance they could have arisen by chance. The only explanation is that something has coded nonsense in a way that poses as a useful message; only after wasting time and effort does the deception becomes apparent. The signal functions to consume the resources of a recipient for zero payoff and reduced fitness. The signal is a virus. Viruses do not arise from kin, symbionts, or other allies. The signal is an attack."
>
>
>
The writing is quite dense and could anyone explains whats the reasoning behind human language being hostile when interpreted by the Rorschach? | 2019/12/17 | [
"https://scifi.stackexchange.com/questions/224521",
"https://scifi.stackexchange.com",
"https://scifi.stackexchange.com/users/124225/"
] | Rorschach is not conscious, which means that it does not spend energy on daydreaming, on emotion, on opinions, or on any part of what we would experience as consciously processing our experiences. This means that to a species like Rorschach, a large part - in fact, the vast majority - of communication between humans is concerning activities that it has no purpose for, and cannot comprehend the need for.
Rorschach only spends energy on things that are directly related to its continued survival. Human activities such as entertainment are therefore considered a complete waste of energy. Even the structure of human language is wasteful - I seem to remember there being a line describing how Rorschach units "time-share" each other's brains. What this means is that Rorschach units don't "speak"; they simply transmit their thoughts in whatever form is more efficient (if I remember correctly, the trapped Rorschach entities communicated by transmitting vibrations through the hull) and each unit continues thinking the recieved thought where the original left off; a true hive-mind, essentially one brain spread across many bodies. Imagine that's how you communicate, then look at the way humans do it: by inventing words with certain meanings, choosing which ones you want to use to express an idea, and then representing those thoughts by a means of sound that includes tonality and stress patterns and tempo, which are all there to indicate social, emotional, and contextual cues... It's tremendously inefficient, from Rorschach's point of view.
When Rorschach encounters this communication, it has to analyse it and work out what it is. Doing so requires understanding all the things I just mentioned, and when it does that, it sees that so much of it is (from Rorschach's perspective) completely unneeded and wasteful. This means that the communication has made Rorschach spend energy on doing something that was ultimately not in any way useful in ensuring its continued survival. Rorschach does not have an unlimited energy budget, which means that by spending some of its energy on understanding human communication, Rorschach is now less able to pursue the activities that it needs to in order to survive.
This means that there is an intelligent creature out there that has done something that has reduced Rorschach's ability to survive. From Rorschach's single-minded perspective, this counts as an attack. The creature who is doing this must be stopped, so that Rorschach no longer has to spend energy on dealing with it, and can instead focus entirely on making its environment safer for Rorschach to live in and ensuring the continuation of its species.
I've tried to phrase this in a way that doesn't imply that Rorschach has opinions or conscious thought; in essence, Rorschach operates solely by what humans would call instinct, reflex, and gut reaction, except vastly more complex; much more direct cause-and-effect and much less reasoning and rationalisation. That's part of what makes Rorschach so scary: it cannot be reasoned with, because it lacks the capability to even think the sort of thoughts that would be required for it to engage in negotiation of the human kind. It cannot be reassured or intimidated, because it is incapable of experiencing fear or concern. The only "negotiation" it would understand is based on actions; humans would have to act in a way that led Rorschach to decide that they are not a threat. Given that this would involve ensuring that Rorschach no longer has to expend any energy in thinking about or reacting to human activities, this is very unlikely. | It's not *all* human language that is interpreted as an attack, it's specifically inter-human messages that *assume consciousness*. Since Rorschach is non-conscious, it doesn't have the terms of reference available to 'understand' those messages.
There are examples given, between the passages you quote. In my 2006 Tor edition, the relevant section starts on p.323 with "Imagine you're a scrambler"
>
> You decode the [intercepted human-to-human] signals, and stumble:
>
>
> *I **had a great time**. I **really enjoyed** him. Even if he cost twice as much as any other hooker in the dome--*
>
>
> *To **fully appreciate** Kesey's Quartet--*
>
>
> *They **hate** us for our freedom--*
>
>
> ***Pay attention**, now--*
>
>
> ***Understand**.*
>
>
>
My emphases indicate the particular parts that would *have no meaning* to a non-conscious intelligence.
You can see the kind of non-conscious language that would *not* be interpreted as an attack, later on after
>
> vampires take over the Earth, and all the humans are killed - the comms Siri picks up from his escape torpedo are "mostly traffic control and telemetry", but "Every now and then I still hear a burst of pure voice, tight with tension ... other ships in **dispassionate** pursuit" - vampires, who as it turns out are also non-conscious, chasing down the last humans.
>
>
> |
45,431 | >
> Chika Ofili, a 12-year-old Nigerian boy based in the United Kingdom, has received the ‘TruLittle Hero Awards’ for discovering a new mathematical formula. [Source](http://www.nigerianeye.com/2019/11/meet-chika-ofili-12-year-old-nigerian.html)
>
>
>
According to the above website (and several others), he envisioned [a simple method to determine if a number is divisible by 7](https://math.stackexchange.com/q/3444466/183815) (which was not included in his textbook), which is amazing on its own!
However, I am bothered by the claim of this being a **new mathematical formula**.
Is this really new? | 2019/11/21 | [
"https://skeptics.stackexchange.com/questions/45431",
"https://skeptics.stackexchange.com",
"https://skeptics.stackexchange.com/users/35504/"
] | This and related divisibility tests are *ancient* and well-known to most who have mastered a first course in elementary number theory. They go back at least a couple hundred years, and possibly even much further (e.g. possibly to circa 1200 given Leonardo Pisano (b.k.a. [Fibonacci](https://en.wikipedia.org/wiki/Fibonacci)) discussed tests for divisibility by 7,9,11 in his [Liber Abaci](https://en.wikipedia.org/wiki/Liber_Abaci) (Book of Calculation))
For example, Dickson's [History, v.1 p. 339](https://archive.org/details/historyoftheoryo01dick/page/339) cites a general divisibility test credited to A. L. Crelle in 1844 which has the above test as a special case. I quote Dickson in the 4 bold lines below:
[](https://i.stack.imgur.com/hyKqt.png)
[](https://i.stack.imgur.com/Fzz7V.png)
[](https://i.stack.imgur.com/fD5Fq.png)
The prior 3 paragraphs are excerpted from one of my [math.SE posts](https://math.stackexchange.com/a/2063944/242), which has further remarks.
Questions about such divisibility tests are FAQs in general-level math forums like math.SE and sci.math. There are thousands of posts discussing such in their archives, including many that explain (in modern language) the above general idea used by Crelle, e.g. [here on math.SE](https://math.stackexchange.com/a/2989299/242). Almost everyone who has mastered a course in elementary number theory knows these ideas well (or could easily derive them if need be).
However, except for a few common cases (e.g. [casting out nines and elevens](https://math.stackexchange.com/a/16015/242)) such divisibility tests generally are not named, nor are they attributed to anyone (which is typical for very old elementary results that are easier to (re)derive than to locate citations for - even more so for results like this that are less useful nowadays given the ubiquity of calculators and computers) | This was published in 1965 as rule no 2 for divisibility by 7 in Vedic Maths. Here’s a blog post from 2009 about it <http://blogannath.blogspot.com/2009/10/vedic-mathematics-lesson-23.html?m=1>
Edit: here’s a Wikipedia link showing Vedic Maths was published in 1965. <https://en.m.wikipedia.org/wiki/Vedic_Maths> |
45,431 | >
> Chika Ofili, a 12-year-old Nigerian boy based in the United Kingdom, has received the ‘TruLittle Hero Awards’ for discovering a new mathematical formula. [Source](http://www.nigerianeye.com/2019/11/meet-chika-ofili-12-year-old-nigerian.html)
>
>
>
According to the above website (and several others), he envisioned [a simple method to determine if a number is divisible by 7](https://math.stackexchange.com/q/3444466/183815) (which was not included in his textbook), which is amazing on its own!
However, I am bothered by the claim of this being a **new mathematical formula**.
Is this really new? | 2019/11/21 | [
"https://skeptics.stackexchange.com/questions/45431",
"https://skeptics.stackexchange.com",
"https://skeptics.stackexchange.com/users/35504/"
] | This and related divisibility tests are *ancient* and well-known to most who have mastered a first course in elementary number theory. They go back at least a couple hundred years, and possibly even much further (e.g. possibly to circa 1200 given Leonardo Pisano (b.k.a. [Fibonacci](https://en.wikipedia.org/wiki/Fibonacci)) discussed tests for divisibility by 7,9,11 in his [Liber Abaci](https://en.wikipedia.org/wiki/Liber_Abaci) (Book of Calculation))
For example, Dickson's [History, v.1 p. 339](https://archive.org/details/historyoftheoryo01dick/page/339) cites a general divisibility test credited to A. L. Crelle in 1844 which has the above test as a special case. I quote Dickson in the 4 bold lines below:
[](https://i.stack.imgur.com/hyKqt.png)
[](https://i.stack.imgur.com/Fzz7V.png)
[](https://i.stack.imgur.com/fD5Fq.png)
The prior 3 paragraphs are excerpted from one of my [math.SE posts](https://math.stackexchange.com/a/2063944/242), which has further remarks.
Questions about such divisibility tests are FAQs in general-level math forums like math.SE and sci.math. There are thousands of posts discussing such in their archives, including many that explain (in modern language) the above general idea used by Crelle, e.g. [here on math.SE](https://math.stackexchange.com/a/2989299/242). Almost everyone who has mastered a course in elementary number theory knows these ideas well (or could easily derive them if need be).
However, except for a few common cases (e.g. [casting out nines and elevens](https://math.stackexchange.com/a/16015/242)) such divisibility tests generally are not named, nor are they attributed to anyone (which is typical for very old elementary results that are easier to (re)derive than to locate citations for - even more so for results like this that are less useful nowadays given the ubiquity of calculators and computers) | If 12 - 13 year primary school student doesn't know algebra & it recognise pattern in math - develop divisibility test then yes it is invention for him.
Is it new discovery in math ?
No.
Test given by Chika is too old. It is also in BKT's 'Vedic Mathematics' book - Published in 1965.
I had given general Theorem (called Cross Divisibility Theorem) to derive divisibility test for any natural number in book
"Modern Approach to Speed Math Secret" published in 2013.
For Video explanation refer
<https://youtu.be/RB9xU0b5AW4> |
2,117 | It has been said many times that the Coordinator is not necessary because its confirmations will be rejected by other nodes if it acts maliciously.
It follows that if other nodes can tell if the Coordinator acts maliciously, then in fact they do not need the Coordinator.
According to [The Transparency Compendium](https://blog.iota.org/the-transparency-compendium-26aa5bb8e260):
>
> This does not mean that the IOTA ledger is currently in any way
> centralized, the network is 100% decentralized, **every node verifies
> that the Coo is is not breaking consensus rules by creating iotas out
> of thin air or approving double-spendings**
>
>
>
According to [eukaryote31](https://webcache.googleusercontent.com/search?q=cache:0-PjedmiS5EJ:https://www.reddit.com/r/Iota/comments/7c3qu8/coordinator_explained) (respected person within IOTA ecosystem):
>
> What if the Coordinator started acting maliciously? Every node looks
> at the transactions it gets and only tells other nodes about
> transactions that are valid. **The Coordinator is no exception, if the
> Coordinator starts issuing bad Milestones, nodes will just reject
> them.**
>
>
>
According to [iota.stackexchange high rated answer](https://iota.stackexchange.com/a/7):
>
> The Coordinator is no exception, if the Coordinator starts issuing bad
> Milestones, nodes will just reject them.
>
>
>
This begs the question, "what makes Coordinator Milestones a security measure if the other nodes are already doing this?" | 2018/08/23 | [
"https://iota.stackexchange.com/questions/2117",
"https://iota.stackexchange.com",
"https://iota.stackexchange.com/users/-1/"
] | There is a link between milestone frequency and average confirmation time. But the time interval between milestone is not a lower bound for confirmation time.
If you submit a tx, and if you are lucky this tx can be immediately selected as tip to approve by a new milestone and you will have a very short confirmation time.
Establishing the exact relationship between milestone frequency and average confirmation time is probably too difficult because many factors comes into the equation like :
* tps
* rate of unfair transactions (i.e. transactions not using the random walk to select tips)
* alpha value
* network topology | I think while we have coordinator fastest confirmation time is limited by frequency how milestones are issued. By definition. Because to be confirmed = to be referenced by milestone.
Average confirmation time must be strongly correlated with the milestone frequency too |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | Whirlpool French door started hitting the new Silestone countertop a few months after the remodel. Dont think the part failed—probably it is due to our 100 year old house tilting. I have just installed high gauss magnets in the upper door hinge and they work perfectly.
[](https://i.stack.imgur.com/UagYv.jpg) | The terms / phrase you want to use with your local home improvement store are "outside corner moulding". I've seen a very broad selection of this at Lowes and Home Depot in my area, so there's bound to be something there that you'd find acceptable. If not, you may be able to find a lexan or polycarbonate outside corner moulding on the internet. Were this my house, I would try to find a 1/2" or 1" moulding that was either clear or a color matching the wall and affix it using epoxy on the inside of the moulding. Clear silicone should do the trick for the clear moulding, any color for a moulding color matching the wall. |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | Most refrigerators have options to swap the side that the refrigerator door is hinged from. If this is an available option on your unit you may want to consider swapping the hinge side so that the door swings open the opposite way.
It is hard to tell from your picture if the unit you have offers this option. If yours is a refrigerator that has split opposing doors down the front then this may not be an option for you. | Cut out wall as shown and replaster:
 |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | The terms / phrase you want to use with your local home improvement store are "outside corner moulding". I've seen a very broad selection of this at Lowes and Home Depot in my area, so there's bound to be something there that you'd find acceptable. If not, you may be able to find a lexan or polycarbonate outside corner moulding on the internet. Were this my house, I would try to find a 1/2" or 1" moulding that was either clear or a color matching the wall and affix it using epoxy on the inside of the moulding. Clear silicone should do the trick for the clear moulding, any color for a moulding color matching the wall. | Cut out wall as shown and replaster:
 |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | Whirlpool French door started hitting the new Silestone countertop a few months after the remodel. Dont think the part failed—probably it is due to our 100 year old house tilting. I have just installed high gauss magnets in the upper door hinge and they work perfectly.
[](https://i.stack.imgur.com/UagYv.jpg) | Pull the fridge forward a little so the door misses the wall. One or two inches should do it. A little testing will tell you how far you need to pull it out.
Also, move it to the left a little if you have room. While many new refrigerators only need a little clear space at the top (1/2" or 1") to vent exhaust air - some need an inch or so on the sides as well. It will perform better when given the proper ventilation space. |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | Pull the fridge forward a little so the door misses the wall. One or two inches should do it. A little testing will tell you how far you need to pull it out.
Also, move it to the left a little if you have room. While many new refrigerators only need a little clear space at the top (1/2" or 1") to vent exhaust air - some need an inch or so on the sides as well. It will perform better when given the proper ventilation space. | Cut out wall as shown and replaster:
 |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | After testing it, I decided that an entire strip of corner molding (or even a section of it) simply looked lousy for this kitchen. After repainting the walls, I found the spot where the door came closest to hitting the edge of the wall. I removed the weak adhesive from a clear, circular vinyl bumper (Everclear brand), and using clear silicone, I glued it into place. The appearance is non-intrusive and it has worked great for months. If it comes off, I have more clear silicone and backup bumpers.
Click below for close-ups.
[](https://i.stack.imgur.com/DNiAK.jpg)
[](https://i.stack.imgur.com/vfxu5.jpg) | Cut out wall as shown and replaster:
 |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | Whirlpool French door started hitting the new Silestone countertop a few months after the remodel. Dont think the part failed—probably it is due to our 100 year old house tilting. I have just installed high gauss magnets in the upper door hinge and they work perfectly.
[](https://i.stack.imgur.com/UagYv.jpg) | Below is a picture of the left door of my LG french door fridge. The right door looks the same. That clear soft plastic thingie, screwed into the base of the cabinet above the fridge, is one of four stoppers that came in a package that I bought at Home Depot. It uses the the grey plastic door hinge, itself, to stop the door from going to far. I installed them above both doors as my fridge sits on a 45 degree angle in the corner of my kitchen, between two granite counter tops. Without the stoppers, the fridge would develop dents whenever the doors hit the granite. Works like a charm and, equally good, you can't see them unless you know they're there and know where to look.
[](https://i.stack.imgur.com/gLv28.jpg) |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | Whirlpool French door started hitting the new Silestone countertop a few months after the remodel. Dont think the part failed—probably it is due to our 100 year old house tilting. I have just installed high gauss magnets in the upper door hinge and they work perfectly.
[](https://i.stack.imgur.com/UagYv.jpg) | After testing it, I decided that an entire strip of corner molding (or even a section of it) simply looked lousy for this kitchen. After repainting the walls, I found the spot where the door came closest to hitting the edge of the wall. I removed the weak adhesive from a clear, circular vinyl bumper (Everclear brand), and using clear silicone, I glued it into place. The appearance is non-intrusive and it has worked great for months. If it comes off, I have more clear silicone and backup bumpers.
Click below for close-ups.
[](https://i.stack.imgur.com/DNiAK.jpg)
[](https://i.stack.imgur.com/vfxu5.jpg) |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | Whirlpool French door started hitting the new Silestone countertop a few months after the remodel. Dont think the part failed—probably it is due to our 100 year old house tilting. I have just installed high gauss magnets in the upper door hinge and they work perfectly.
[](https://i.stack.imgur.com/UagYv.jpg) | Cut out wall as shown and replaster:
 |
66,503 | I have a stainless steel counter-depth refrigerator door (LG LFXC24726S). The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.
Per the photos, I have placed three small clear rubber bumps between the door and the wall, but
1. they look ugly
2. they keep shifting, so I'd have to glue them in place
I need to find a solution that is not visually intrusive, but creates a good barrier. One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).
Alternately, I need some form of bumper, but I don't quite know what to search on/for. I'd prefer something clear that won't scratch the door. I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (*ostensibly, "the internet" once I know what to search for*).
Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?
**Bumpers Detail.** *Click for full size image*
[](https://i.stack.imgur.com/i5VXf.jpg)
**Open Door Detail.** *Click for full size image*
[](https://i.stack.imgur.com/K9eX1.jpg) | 2015/05/22 | [
"https://diy.stackexchange.com/questions/66503",
"https://diy.stackexchange.com",
"https://diy.stackexchange.com/users/11845/"
] | Below is a picture of the left door of my LG french door fridge. The right door looks the same. That clear soft plastic thingie, screwed into the base of the cabinet above the fridge, is one of four stoppers that came in a package that I bought at Home Depot. It uses the the grey plastic door hinge, itself, to stop the door from going to far. I installed them above both doors as my fridge sits on a 45 degree angle in the corner of my kitchen, between two granite counter tops. Without the stoppers, the fridge would develop dents whenever the doors hit the granite. Works like a charm and, equally good, you can't see them unless you know they're there and know where to look.
[](https://i.stack.imgur.com/gLv28.jpg) | Cut out wall as shown and replaster:
 |
32,887 | As part of a registration form I am building I need to, at some point, differentiate between whether the user is a 'student' or 'professor'. I've seen this handled in two different ways and was curious if anyone had any thoughts or research on the benefits/downsides of each way.
Two separate sign-up buttons on homepage
[www.lore.com](http://www.lore.com) and
[www.piazza.com](http://www.piazza.com)
One sign-up button, then two choices as part of the sign-up flow
[www.schoology.com](http://www.schoology.com)
The first method is one less click for the user but can potentially make the homepage more confusing with two call to action buttons next to each other. Also, with the first method, you couldn't just have a single 'sign-up' button elsewhere on the site, you'd have to provide two 'sign-up' options at all times. | 2013/01/14 | [
"https://ux.stackexchange.com/questions/32887",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/21065/"
] | As long as you are not capturing different attributes for different types of users, don't give a different sign-up links. If the attributes you are capturing are almost same, then no need to give two sign-up links.
A fitting example of different sign-ups for different type of users would be www.iwriter.com where you can sign-up as publisher and advertiser. | You could use [paypal](https://www.paypal.com/uk/cgi-bin/webscr?cmd=_flow&SESSION=0Sl1tPLWqmtOlGOXgzEwkSQHYGJRnq4WK78iq1Lh5WH5fO-qKVvh-NwxMtq&dispatch=5885d80a13c0db1f8e263663d3faee8d0b7e678a25d883d0fa72c947f193f8fd) method its similar to the lore.com. As well Lore does it well big images big buttons there is almost 0% of mistake piazza is a bit harder, especially for children.
Another way you could incorporate this selection in to the form for example you can have a radio button as a 1st question in the sign up form "Student" or "Teacher" and then display relevant form. |
32,887 | As part of a registration form I am building I need to, at some point, differentiate between whether the user is a 'student' or 'professor'. I've seen this handled in two different ways and was curious if anyone had any thoughts or research on the benefits/downsides of each way.
Two separate sign-up buttons on homepage
[www.lore.com](http://www.lore.com) and
[www.piazza.com](http://www.piazza.com)
One sign-up button, then two choices as part of the sign-up flow
[www.schoology.com](http://www.schoology.com)
The first method is one less click for the user but can potentially make the homepage more confusing with two call to action buttons next to each other. Also, with the first method, you couldn't just have a single 'sign-up' button elsewhere on the site, you'd have to provide two 'sign-up' options at all times. | 2013/01/14 | [
"https://ux.stackexchange.com/questions/32887",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/21065/"
] | **Don't make people think** before they have made a commitment to sign up (by selecting a sign up button). Every time you make a potential customer think you create an opportunity for then to choose not to and leave your site. It's also much harder to later optimise your page when you have two sign up buttons, as suddenly there are more variables to consider.
**Go for one sign up button** and then give an option early on in the sign up process for them to choose what they are signing up for.
---
As a side note, have you considered the case where they are both a professor and a student? I know many professors and lecturers that are always studying. | You could use [paypal](https://www.paypal.com/uk/cgi-bin/webscr?cmd=_flow&SESSION=0Sl1tPLWqmtOlGOXgzEwkSQHYGJRnq4WK78iq1Lh5WH5fO-qKVvh-NwxMtq&dispatch=5885d80a13c0db1f8e263663d3faee8d0b7e678a25d883d0fa72c947f193f8fd) method its similar to the lore.com. As well Lore does it well big images big buttons there is almost 0% of mistake piazza is a bit harder, especially for children.
Another way you could incorporate this selection in to the form for example you can have a radio button as a 1st question in the sign up form "Student" or "Teacher" and then display relevant form. |
32,887 | As part of a registration form I am building I need to, at some point, differentiate between whether the user is a 'student' or 'professor'. I've seen this handled in two different ways and was curious if anyone had any thoughts or research on the benefits/downsides of each way.
Two separate sign-up buttons on homepage
[www.lore.com](http://www.lore.com) and
[www.piazza.com](http://www.piazza.com)
One sign-up button, then two choices as part of the sign-up flow
[www.schoology.com](http://www.schoology.com)
The first method is one less click for the user but can potentially make the homepage more confusing with two call to action buttons next to each other. Also, with the first method, you couldn't just have a single 'sign-up' button elsewhere on the site, you'd have to provide two 'sign-up' options at all times. | 2013/01/14 | [
"https://ux.stackexchange.com/questions/32887",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/21065/"
] | I would say that it depends on what you are doing with the distinction.
For example - if the product that the "professor" gets is substantially the same that the product and benefits that the "student", and you're asking for the same information on both, then I'd stick to a single sign up button.
If the professor is getting a different kind of product, or if the value that the professor gets is from the same product is very different from that of the student, then separate sign up forms may be more effective.
For example you could trickle copy highlighting the value that the professor gets on the professor sign up page. Ditto for the student.
Depending on the value of the different customer types to the business it might also be of value to have separate sign up forms so you can track and optimise the conversion funnel for each group separately. | You could use [paypal](https://www.paypal.com/uk/cgi-bin/webscr?cmd=_flow&SESSION=0Sl1tPLWqmtOlGOXgzEwkSQHYGJRnq4WK78iq1Lh5WH5fO-qKVvh-NwxMtq&dispatch=5885d80a13c0db1f8e263663d3faee8d0b7e678a25d883d0fa72c947f193f8fd) method its similar to the lore.com. As well Lore does it well big images big buttons there is almost 0% of mistake piazza is a bit harder, especially for children.
Another way you could incorporate this selection in to the form for example you can have a radio button as a 1st question in the sign up form "Student" or "Teacher" and then display relevant form. |
32,887 | As part of a registration form I am building I need to, at some point, differentiate between whether the user is a 'student' or 'professor'. I've seen this handled in two different ways and was curious if anyone had any thoughts or research on the benefits/downsides of each way.
Two separate sign-up buttons on homepage
[www.lore.com](http://www.lore.com) and
[www.piazza.com](http://www.piazza.com)
One sign-up button, then two choices as part of the sign-up flow
[www.schoology.com](http://www.schoology.com)
The first method is one less click for the user but can potentially make the homepage more confusing with two call to action buttons next to each other. Also, with the first method, you couldn't just have a single 'sign-up' button elsewhere on the site, you'd have to provide two 'sign-up' options at all times. | 2013/01/14 | [
"https://ux.stackexchange.com/questions/32887",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/21065/"
] | **Don't make people think** before they have made a commitment to sign up (by selecting a sign up button). Every time you make a potential customer think you create an opportunity for then to choose not to and leave your site. It's also much harder to later optimise your page when you have two sign up buttons, as suddenly there are more variables to consider.
**Go for one sign up button** and then give an option early on in the sign up process for them to choose what they are signing up for.
---
As a side note, have you considered the case where they are both a professor and a student? I know many professors and lecturers that are always studying. | As long as you are not capturing different attributes for different types of users, don't give a different sign-up links. If the attributes you are capturing are almost same, then no need to give two sign-up links.
A fitting example of different sign-ups for different type of users would be www.iwriter.com where you can sign-up as publisher and advertiser. |
32,887 | As part of a registration form I am building I need to, at some point, differentiate between whether the user is a 'student' or 'professor'. I've seen this handled in two different ways and was curious if anyone had any thoughts or research on the benefits/downsides of each way.
Two separate sign-up buttons on homepage
[www.lore.com](http://www.lore.com) and
[www.piazza.com](http://www.piazza.com)
One sign-up button, then two choices as part of the sign-up flow
[www.schoology.com](http://www.schoology.com)
The first method is one less click for the user but can potentially make the homepage more confusing with two call to action buttons next to each other. Also, with the first method, you couldn't just have a single 'sign-up' button elsewhere on the site, you'd have to provide two 'sign-up' options at all times. | 2013/01/14 | [
"https://ux.stackexchange.com/questions/32887",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/21065/"
] | As long as you are not capturing different attributes for different types of users, don't give a different sign-up links. If the attributes you are capturing are almost same, then no need to give two sign-up links.
A fitting example of different sign-ups for different type of users would be www.iwriter.com where you can sign-up as publisher and advertiser. | I would say that it depends on what you are doing with the distinction.
For example - if the product that the "professor" gets is substantially the same that the product and benefits that the "student", and you're asking for the same information on both, then I'd stick to a single sign up button.
If the professor is getting a different kind of product, or if the value that the professor gets is from the same product is very different from that of the student, then separate sign up forms may be more effective.
For example you could trickle copy highlighting the value that the professor gets on the professor sign up page. Ditto for the student.
Depending on the value of the different customer types to the business it might also be of value to have separate sign up forms so you can track and optimise the conversion funnel for each group separately. |
32,887 | As part of a registration form I am building I need to, at some point, differentiate between whether the user is a 'student' or 'professor'. I've seen this handled in two different ways and was curious if anyone had any thoughts or research on the benefits/downsides of each way.
Two separate sign-up buttons on homepage
[www.lore.com](http://www.lore.com) and
[www.piazza.com](http://www.piazza.com)
One sign-up button, then two choices as part of the sign-up flow
[www.schoology.com](http://www.schoology.com)
The first method is one less click for the user but can potentially make the homepage more confusing with two call to action buttons next to each other. Also, with the first method, you couldn't just have a single 'sign-up' button elsewhere on the site, you'd have to provide two 'sign-up' options at all times. | 2013/01/14 | [
"https://ux.stackexchange.com/questions/32887",
"https://ux.stackexchange.com",
"https://ux.stackexchange.com/users/21065/"
] | **Don't make people think** before they have made a commitment to sign up (by selecting a sign up button). Every time you make a potential customer think you create an opportunity for then to choose not to and leave your site. It's also much harder to later optimise your page when you have two sign up buttons, as suddenly there are more variables to consider.
**Go for one sign up button** and then give an option early on in the sign up process for them to choose what they are signing up for.
---
As a side note, have you considered the case where they are both a professor and a student? I know many professors and lecturers that are always studying. | I would say that it depends on what you are doing with the distinction.
For example - if the product that the "professor" gets is substantially the same that the product and benefits that the "student", and you're asking for the same information on both, then I'd stick to a single sign up button.
If the professor is getting a different kind of product, or if the value that the professor gets is from the same product is very different from that of the student, then separate sign up forms may be more effective.
For example you could trickle copy highlighting the value that the professor gets on the professor sign up page. Ditto for the student.
Depending on the value of the different customer types to the business it might also be of value to have separate sign up forms so you can track and optimise the conversion funnel for each group separately. |
87,389 | Can you recommend me a good antivirus for windows server 2008?
Please send the download URL, because i downloaded many and while installing it tell me that the system is not supported.
i want any antivirus trial version so i can try before buy. | 2009/11/23 | [
"https://serverfault.com/questions/87389",
"https://serverfault.com",
"https://serverfault.com/users/978/"
] | [Register with McAfee](https://secure.nai.com/apps/downloads/free_evaluations/survey.asp?type=d&prodid=2796&mktg=ESD345&bu=McAfee®ion=us&segment=small&RefreshPartner=UNITED%20STATES), and then download [McAfee ViruScan Enterprise 8.5i](http://www.mcafee.com/us/enterprise/products/system_security/servers/virusscan_enterprise.html). It'll run on all versions of Windows Server 2008, and it's pretty much the same as all the other virus scanners for Windows Server products. | AVG Business Version
This is the professional level version of AVG, not the free edition. You can get the standalone clients or go all out with a dedicated AVG server to manage client installs of AVG.
You can download trials and read more at: <http://www.avg.com/us-en/download>
I have used this one personaly in a corporate environment and it works quite well. |
87,389 | Can you recommend me a good antivirus for windows server 2008?
Please send the download URL, because i downloaded many and while installing it tell me that the system is not supported.
i want any antivirus trial version so i can try before buy. | 2009/11/23 | [
"https://serverfault.com/questions/87389",
"https://serverfault.com",
"https://serverfault.com/users/978/"
] | [Register with McAfee](https://secure.nai.com/apps/downloads/free_evaluations/survey.asp?type=d&prodid=2796&mktg=ESD345&bu=McAfee®ion=us&segment=small&RefreshPartner=UNITED%20STATES), and then download [McAfee ViruScan Enterprise 8.5i](http://www.mcafee.com/us/enterprise/products/system_security/servers/virusscan_enterprise.html). It'll run on all versions of Windows Server 2008, and it's pretty much the same as all the other virus scanners for Windows Server products. | The reason most anti-virus applications are failiing to install is because you're installing them on a 'server' rather than a 'client'. Alot of those application will check and make sure that it's not being installed on a server on purpose.
You can also download a trialware version of [Symantec Endpoint Protection](http://www.symantec.com/business/products/trialware.jsp?pcid=pcat_security&pvid=endpt_prot_1) and test that application on your server also.
Good luck and hope this helps some. |
6,867,175 | is there a plugin or some configuration in Hudson CI where the job will not run during a certain time of day? I was thinking of a job like:
Run job A on version control change if not after 5pm and before 9am
Thanks! | 2011/07/28 | [
"https://Stackoverflow.com/questions/6867175",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/288570/"
] | Maybe you could set up a global property that gets set to on/off depending on time and you configure the builds to use that global property.
But the best way would probably to set up the scm polling to just not poll at the desired time of day. Then no changes are found and no build is triggered ;-) | We run automated tests in our Jenkins instance. When these are being run on certain environments, we disable the deploy job to the involved environments. This is done using Jenkins CLI. <https://wiki.jenkins-ci.org/display/JENKINS/Jenkins+CLI>
I bet you could do the same thing but instead use the "Build periodically" function in the job. |
49,883 | Mentioning a book to an individual to include in their list as *classic* was met with...
>
> I wouldn't call "Book Name" a classic - it's less than 11 years
> old.
>
>
>
This got me thinking about when a book or other item (car, slang, recipe, etc...) becomes a *classic*. In my initial investigation I stumbled upon this description...
>
> A novel can be called a classic when there is a significant time
> period between its publishing and the current age we are in. In other
> words, it has to be old, as well as critically renowned as a good
> novel. Then, it can be called a classic.
>
>
>
While the above may help define what constitutes a classic, it doesn't define the amount of time that needs to pass before that criteria is met.
Does the designation *classic* truly imply that a significant amount of time has passed since the work's creation, and if so, how long must that period be to qualify as "significant"? | 2011/11/28 | [
"https://english.stackexchange.com/questions/49883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/5612/"
] | *Classic* as explained at [etymonline.com](http://www.etymonline.com/index.php?search=classic) historically referred to standard authors of Greek and Roman antiquity. As an [adjective and noun](http://en.wiktionary.org/wiki/classic) it now means (a) "1, exemplary of a particular style; 2, exhibiting timeless quality" and (n) "1, a perfect and/or early example of a particular style; 2,an artistic work of lasting worth". Some books, films, and artistic works are of obvious quality when they first appear; others are not; any can be called classic in either sense even when they first appear. Some judgments hold, some do not.
An [ngrams](http://books.google.com/ngrams/graph?content=instant+classic%2Cold+classic%2Cnew+classic%2Cfavorite+classic&year_start=1970&year_end=2006&corpus=0&smoothing=3) for "instant classic,old classic,new classic,favorite classic" in recent years shows rising use of "instant classic". 
For some reason, use of "favorite classic" has [exploded since 2006](http://books.google.com/ngrams/graph?content=instant+classic%2Cold+classic%2Cnew+classic%2Cfavorite+classic&year_start=1970&year_end=2010&corpus=0&smoothing=3). | There is no definite length of time which must pass before something becomes a classic. The requirement is that sufficient time has passed during which it becomes famous because of its quality. |
49,883 | Mentioning a book to an individual to include in their list as *classic* was met with...
>
> I wouldn't call "Book Name" a classic - it's less than 11 years
> old.
>
>
>
This got me thinking about when a book or other item (car, slang, recipe, etc...) becomes a *classic*. In my initial investigation I stumbled upon this description...
>
> A novel can be called a classic when there is a significant time
> period between its publishing and the current age we are in. In other
> words, it has to be old, as well as critically renowned as a good
> novel. Then, it can be called a classic.
>
>
>
While the above may help define what constitutes a classic, it doesn't define the amount of time that needs to pass before that criteria is met.
Does the designation *classic* truly imply that a significant amount of time has passed since the work's creation, and if so, how long must that period be to qualify as "significant"? | 2011/11/28 | [
"https://english.stackexchange.com/questions/49883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/5612/"
] | Time, as they say in contracts, is not of the essence. For the OED, a classic is:
>
> A work of literature, music, or art of acknowledged quality and
> enduring significance or popularity. In extended use: something which
> is memorable and an outstanding example of its kind.
>
>
>
The entry is silent on how long it must endure to be of ***enduring*** significance or popularity. | There is no definite length of time which must pass before something becomes a classic. The requirement is that sufficient time has passed during which it becomes famous because of its quality. |
49,883 | Mentioning a book to an individual to include in their list as *classic* was met with...
>
> I wouldn't call "Book Name" a classic - it's less than 11 years
> old.
>
>
>
This got me thinking about when a book or other item (car, slang, recipe, etc...) becomes a *classic*. In my initial investigation I stumbled upon this description...
>
> A novel can be called a classic when there is a significant time
> period between its publishing and the current age we are in. In other
> words, it has to be old, as well as critically renowned as a good
> novel. Then, it can be called a classic.
>
>
>
While the above may help define what constitutes a classic, it doesn't define the amount of time that needs to pass before that criteria is met.
Does the designation *classic* truly imply that a significant amount of time has passed since the work's creation, and if so, how long must that period be to qualify as "significant"? | 2011/11/28 | [
"https://english.stackexchange.com/questions/49883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/5612/"
] | There is no definite length of time which must pass before something becomes a classic. The requirement is that sufficient time has passed during which it becomes famous because of its quality. | To qualify as a classic, it should have stood the test of time. If a model of a car has been discontinued and no other model has earned as much acceptance in the time that usually takes for the older models to be forgotten in the light of newer, better ones, then the nice old model is rightly a *classic*!
Applies equally well to literature or recipes? |
49,883 | Mentioning a book to an individual to include in their list as *classic* was met with...
>
> I wouldn't call "Book Name" a classic - it's less than 11 years
> old.
>
>
>
This got me thinking about when a book or other item (car, slang, recipe, etc...) becomes a *classic*. In my initial investigation I stumbled upon this description...
>
> A novel can be called a classic when there is a significant time
> period between its publishing and the current age we are in. In other
> words, it has to be old, as well as critically renowned as a good
> novel. Then, it can be called a classic.
>
>
>
While the above may help define what constitutes a classic, it doesn't define the amount of time that needs to pass before that criteria is met.
Does the designation *classic* truly imply that a significant amount of time has passed since the work's creation, and if so, how long must that period be to qualify as "significant"? | 2011/11/28 | [
"https://english.stackexchange.com/questions/49883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/5612/"
] | Time, as they say in contracts, is not of the essence. For the OED, a classic is:
>
> A work of literature, music, or art of acknowledged quality and
> enduring significance or popularity. In extended use: something which
> is memorable and an outstanding example of its kind.
>
>
>
The entry is silent on how long it must endure to be of ***enduring*** significance or popularity. | *Classic* as explained at [etymonline.com](http://www.etymonline.com/index.php?search=classic) historically referred to standard authors of Greek and Roman antiquity. As an [adjective and noun](http://en.wiktionary.org/wiki/classic) it now means (a) "1, exemplary of a particular style; 2, exhibiting timeless quality" and (n) "1, a perfect and/or early example of a particular style; 2,an artistic work of lasting worth". Some books, films, and artistic works are of obvious quality when they first appear; others are not; any can be called classic in either sense even when they first appear. Some judgments hold, some do not.
An [ngrams](http://books.google.com/ngrams/graph?content=instant+classic%2Cold+classic%2Cnew+classic%2Cfavorite+classic&year_start=1970&year_end=2006&corpus=0&smoothing=3) for "instant classic,old classic,new classic,favorite classic" in recent years shows rising use of "instant classic". 
For some reason, use of "favorite classic" has [exploded since 2006](http://books.google.com/ngrams/graph?content=instant+classic%2Cold+classic%2Cnew+classic%2Cfavorite+classic&year_start=1970&year_end=2010&corpus=0&smoothing=3). |
49,883 | Mentioning a book to an individual to include in their list as *classic* was met with...
>
> I wouldn't call "Book Name" a classic - it's less than 11 years
> old.
>
>
>
This got me thinking about when a book or other item (car, slang, recipe, etc...) becomes a *classic*. In my initial investigation I stumbled upon this description...
>
> A novel can be called a classic when there is a significant time
> period between its publishing and the current age we are in. In other
> words, it has to be old, as well as critically renowned as a good
> novel. Then, it can be called a classic.
>
>
>
While the above may help define what constitutes a classic, it doesn't define the amount of time that needs to pass before that criteria is met.
Does the designation *classic* truly imply that a significant amount of time has passed since the work's creation, and if so, how long must that period be to qualify as "significant"? | 2011/11/28 | [
"https://english.stackexchange.com/questions/49883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/5612/"
] | *Classic* as explained at [etymonline.com](http://www.etymonline.com/index.php?search=classic) historically referred to standard authors of Greek and Roman antiquity. As an [adjective and noun](http://en.wiktionary.org/wiki/classic) it now means (a) "1, exemplary of a particular style; 2, exhibiting timeless quality" and (n) "1, a perfect and/or early example of a particular style; 2,an artistic work of lasting worth". Some books, films, and artistic works are of obvious quality when they first appear; others are not; any can be called classic in either sense even when they first appear. Some judgments hold, some do not.
An [ngrams](http://books.google.com/ngrams/graph?content=instant+classic%2Cold+classic%2Cnew+classic%2Cfavorite+classic&year_start=1970&year_end=2006&corpus=0&smoothing=3) for "instant classic,old classic,new classic,favorite classic" in recent years shows rising use of "instant classic". 
For some reason, use of "favorite classic" has [exploded since 2006](http://books.google.com/ngrams/graph?content=instant+classic%2Cold+classic%2Cnew+classic%2Cfavorite+classic&year_start=1970&year_end=2010&corpus=0&smoothing=3). | To qualify as a classic, it should have stood the test of time. If a model of a car has been discontinued and no other model has earned as much acceptance in the time that usually takes for the older models to be forgotten in the light of newer, better ones, then the nice old model is rightly a *classic*!
Applies equally well to literature or recipes? |
49,883 | Mentioning a book to an individual to include in their list as *classic* was met with...
>
> I wouldn't call "Book Name" a classic - it's less than 11 years
> old.
>
>
>
This got me thinking about when a book or other item (car, slang, recipe, etc...) becomes a *classic*. In my initial investigation I stumbled upon this description...
>
> A novel can be called a classic when there is a significant time
> period between its publishing and the current age we are in. In other
> words, it has to be old, as well as critically renowned as a good
> novel. Then, it can be called a classic.
>
>
>
While the above may help define what constitutes a classic, it doesn't define the amount of time that needs to pass before that criteria is met.
Does the designation *classic* truly imply that a significant amount of time has passed since the work's creation, and if so, how long must that period be to qualify as "significant"? | 2011/11/28 | [
"https://english.stackexchange.com/questions/49883",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/5612/"
] | Time, as they say in contracts, is not of the essence. For the OED, a classic is:
>
> A work of literature, music, or art of acknowledged quality and
> enduring significance or popularity. In extended use: something which
> is memorable and an outstanding example of its kind.
>
>
>
The entry is silent on how long it must endure to be of ***enduring*** significance or popularity. | To qualify as a classic, it should have stood the test of time. If a model of a car has been discontinued and no other model has earned as much acceptance in the time that usually takes for the older models to be forgotten in the light of newer, better ones, then the nice old model is rightly a *classic*!
Applies equally well to literature or recipes? |
74,668 | I'm not a big fan of spending 100ish dollars to buy all three core rulebooks. Are there monster stats to be found online? Also, is there an online substitute for the DMG (for items)? | 2016/02/14 | [
"https://rpg.stackexchange.com/questions/74668",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/27249/"
] | A site called [Open5e](http://open5e.com/) recently launched that has everything from the SRD: rules, GM guide, character creation guide, spell list, some monsters, and equipment.
It's easily searchable and it's open source, so people can contribute more info if there's anything they've missed. | You can also look to Fantasy Grounds (www.fantasygrounds.net). It is an online campaign manager for D&D, and other game systems. It has the rulebooks built into its libraries, and allows the creation of all the hard cover printed books. You also have options to create your classes/abilities/etc. |
74,668 | I'm not a big fan of spending 100ish dollars to buy all three core rulebooks. Are there monster stats to be found online? Also, is there an online substitute for the DMG (for items)? | 2016/02/14 | [
"https://rpg.stackexchange.com/questions/74668",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/27249/"
] | There are a few things.
* The basic rules for [players](http://media.wizards.com/2015/downloads/dnd/BasicRules_Playerv3.4.pdf) and [Dungeon Masters](http://media.wizards.com/2015/downloads/dnd/DMBasicRules.pdf) provide all the information needed to start play, but not much in the way of monster stats.
* The [Systems Reference Document](http://media.wizards.com/2016/downloads/SRD-OGL_V1.1.pdf) ("the SRD") includes a subset of the monsters from the Monster Manual and the magic items in the Dungeon Master's Guide. All of the information from the SRD can be found (and searched) on [open5e](http://open5e.com/), which may be more convenient than a monolithic PDF. | A site called [Open5e](http://open5e.com/) recently launched that has everything from the SRD: rules, GM guide, character creation guide, spell list, some monsters, and equipment.
It's easily searchable and it's open source, so people can contribute more info if there's anything they've missed. |
74,668 | I'm not a big fan of spending 100ish dollars to buy all three core rulebooks. Are there monster stats to be found online? Also, is there an online substitute for the DMG (for items)? | 2016/02/14 | [
"https://rpg.stackexchange.com/questions/74668",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/27249/"
] | There are a few things.
* The basic rules for [players](http://media.wizards.com/2015/downloads/dnd/BasicRules_Playerv3.4.pdf) and [Dungeon Masters](http://media.wizards.com/2015/downloads/dnd/DMBasicRules.pdf) provide all the information needed to start play, but not much in the way of monster stats.
* The [Systems Reference Document](http://media.wizards.com/2016/downloads/SRD-OGL_V1.1.pdf) ("the SRD") includes a subset of the monsters from the Monster Manual and the magic items in the Dungeon Master's Guide. All of the information from the SRD can be found (and searched) on [open5e](http://open5e.com/), which may be more convenient than a monolithic PDF. | You can also look to Fantasy Grounds (www.fantasygrounds.net). It is an online campaign manager for D&D, and other game systems. It has the rulebooks built into its libraries, and allows the creation of all the hard cover printed books. You also have options to create your classes/abilities/etc. |
74,668 | I'm not a big fan of spending 100ish dollars to buy all three core rulebooks. Are there monster stats to be found online? Also, is there an online substitute for the DMG (for items)? | 2016/02/14 | [
"https://rpg.stackexchange.com/questions/74668",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/27249/"
] | WotC has released free PDFs that provide you with *some* of the content from the PHB, DMG, and MM:
* [Basic Rules](http://dnd.wizards.com/articles/features/basicrules) - Apart from the core rules information, the Players' PDF gives you the most iconic D&D classes and races, and a small selection of spells. The DM's PDF gives you a small collection of monsters and magic items. They can also be viewed online - [Players](http://dnd.wizards.com/products/tabletop/players-basic-rules) / [DMs](http://dnd.wizards.com/products/tabletop/dm-basic-rules).
* [SRD](http://dnd.wizards.com/articles/features/systems-reference-document-srd) - All the races from the PHB (but only one subrace of each), and all the classes (but only one class option template for each), and a good selection of spells, monsters & magic items. There are also 3rd-party sites that lets you view (and search) the SRD online: [Open5e](http://open5e.com/) or [5e SRD](http://www.5esrd.com/). Also, [D&D Beyond](https://www.dndbeyond.com/sources/basic-rules) combines the Basic Rules and SRD into one, but just calls it Basic Rules.
* [Elemental Evil Player's Companion](http://dnd.wizards.com/articles/features/elementalevil_playerscompanion) - All the spells referenced in the Elemental Evil adventure that weren't in the Basic rules, and a few new races.
* There are also supplements for [Hoard of the Dragon Queen](http://dnd.wizards.com/products/tabletop-games/rpg-products/hoard-dragon-queen), [Princes of the Apocalypse](http://dnd.wizards.com/products/tabletop-games/rpg-products/princes-apocalypse), and [Rise of Tiamat](http://dnd.wizards.com/products/tabletop-games/rpg-products/rise-tiamat) that detail all the spells, monsters, and magic items referenced in those adventures that weren't in the Basic rules.
(I have created [an index of all the above documents](http://www.enworld.org/forum/showthread.php?477146-The-Cheapskate-Index-An-index-to-WotC-s-free-PDFs) that you may find useful)
You may also be interested in the [Unearthed Arcana](http://dnd.wizards.com/search/site/unearthed%2520arcana) articles, that detail not-fully-tested options. These may or may not appear in later books, in modified form.
There are also 3rd-party supplements on the [Dungeonmasters Guild](http://www.dmsguild.com/browse.php?pto=0&pfrom=0), some of which are free. | A site called [Open5e](http://open5e.com/) recently launched that has everything from the SRD: rules, GM guide, character creation guide, spell list, some monsters, and equipment.
It's easily searchable and it's open source, so people can contribute more info if there's anything they've missed. |
74,668 | I'm not a big fan of spending 100ish dollars to buy all three core rulebooks. Are there monster stats to be found online? Also, is there an online substitute for the DMG (for items)? | 2016/02/14 | [
"https://rpg.stackexchange.com/questions/74668",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/27249/"
] | As well as the free [Basic Rules](http://dnd.wizards.com/articles/features/basicrules), there are a number of online supplements, most of which contain monsters and magic items.
* [Hoard of the Dragon Queen](https://dnd.wizards.com/products/tabletop-games/rpg-products/hoard-dragon-queen)
* [The Rise of Tiamat](http://dnd.wizards.com/products/tabletop-games/rpg-products/rise-tiamat)
* [Princes of the Apocalypse](http://dnd.wizards.com/products/tabletop-games/rpg-products/princes-apocalypse)
I remember a thread a year or so ago where one of Wizard's staff said you can play the game by buying one book. I believe they suggested the Monster Manual. That is, use the free Basic Rules and the purchased MM. The idea was that reading the monster stats gave lots of cool ideas for adventures.
Personally, I think that buying the PHB is a no-brainer. The Basic rules only give you a few classes and archetypes; the PHB gives you all of them. Add the free Elemental Evil Player's Companion for a few more races and spells.
You may want to borrow the Sword Coast Adventurer's Guide before you read it. I'm hearing mixed reviews, and more than a few people are telling me not to waste money on it. YMMV.
I would also suggest [D&D Classics](http://www.dmsguild.com/browse.php?filters=45471_0_0_0_0_0). A few dollars there will get you old d&d adventures that work very well in 5th edition. I've found that 1st ed modules need very little conversion (just picking appropriate monsters for the party level). | You can also look to Fantasy Grounds (www.fantasygrounds.net). It is an online campaign manager for D&D, and other game systems. It has the rulebooks built into its libraries, and allows the creation of all the hard cover printed books. You also have options to create your classes/abilities/etc. |
74,668 | I'm not a big fan of spending 100ish dollars to buy all three core rulebooks. Are there monster stats to be found online? Also, is there an online substitute for the DMG (for items)? | 2016/02/14 | [
"https://rpg.stackexchange.com/questions/74668",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/27249/"
] | WotC has released free PDFs that provide you with *some* of the content from the PHB, DMG, and MM:
* [Basic Rules](http://dnd.wizards.com/articles/features/basicrules) - Apart from the core rules information, the Players' PDF gives you the most iconic D&D classes and races, and a small selection of spells. The DM's PDF gives you a small collection of monsters and magic items. They can also be viewed online - [Players](http://dnd.wizards.com/products/tabletop/players-basic-rules) / [DMs](http://dnd.wizards.com/products/tabletop/dm-basic-rules).
* [SRD](http://dnd.wizards.com/articles/features/systems-reference-document-srd) - All the races from the PHB (but only one subrace of each), and all the classes (but only one class option template for each), and a good selection of spells, monsters & magic items. There are also 3rd-party sites that lets you view (and search) the SRD online: [Open5e](http://open5e.com/) or [5e SRD](http://www.5esrd.com/). Also, [D&D Beyond](https://www.dndbeyond.com/sources/basic-rules) combines the Basic Rules and SRD into one, but just calls it Basic Rules.
* [Elemental Evil Player's Companion](http://dnd.wizards.com/articles/features/elementalevil_playerscompanion) - All the spells referenced in the Elemental Evil adventure that weren't in the Basic rules, and a few new races.
* There are also supplements for [Hoard of the Dragon Queen](http://dnd.wizards.com/products/tabletop-games/rpg-products/hoard-dragon-queen), [Princes of the Apocalypse](http://dnd.wizards.com/products/tabletop-games/rpg-products/princes-apocalypse), and [Rise of Tiamat](http://dnd.wizards.com/products/tabletop-games/rpg-products/rise-tiamat) that detail all the spells, monsters, and magic items referenced in those adventures that weren't in the Basic rules.
(I have created [an index of all the above documents](http://www.enworld.org/forum/showthread.php?477146-The-Cheapskate-Index-An-index-to-WotC-s-free-PDFs) that you may find useful)
You may also be interested in the [Unearthed Arcana](http://dnd.wizards.com/search/site/unearthed%2520arcana) articles, that detail not-fully-tested options. These may or may not appear in later books, in modified form.
There are also 3rd-party supplements on the [Dungeonmasters Guild](http://www.dmsguild.com/browse.php?pto=0&pfrom=0), some of which are free. | You can also look to Fantasy Grounds (www.fantasygrounds.net). It is an online campaign manager for D&D, and other game systems. It has the rulebooks built into its libraries, and allows the creation of all the hard cover printed books. You also have options to create your classes/abilities/etc. |
74,668 | I'm not a big fan of spending 100ish dollars to buy all three core rulebooks. Are there monster stats to be found online? Also, is there an online substitute for the DMG (for items)? | 2016/02/14 | [
"https://rpg.stackexchange.com/questions/74668",
"https://rpg.stackexchange.com",
"https://rpg.stackexchange.com/users/27249/"
] | WotC has released free PDFs that provide you with *some* of the content from the PHB, DMG, and MM:
* [Basic Rules](http://dnd.wizards.com/articles/features/basicrules) - Apart from the core rules information, the Players' PDF gives you the most iconic D&D classes and races, and a small selection of spells. The DM's PDF gives you a small collection of monsters and magic items. They can also be viewed online - [Players](http://dnd.wizards.com/products/tabletop/players-basic-rules) / [DMs](http://dnd.wizards.com/products/tabletop/dm-basic-rules).
* [SRD](http://dnd.wizards.com/articles/features/systems-reference-document-srd) - All the races from the PHB (but only one subrace of each), and all the classes (but only one class option template for each), and a good selection of spells, monsters & magic items. There are also 3rd-party sites that lets you view (and search) the SRD online: [Open5e](http://open5e.com/) or [5e SRD](http://www.5esrd.com/). Also, [D&D Beyond](https://www.dndbeyond.com/sources/basic-rules) combines the Basic Rules and SRD into one, but just calls it Basic Rules.
* [Elemental Evil Player's Companion](http://dnd.wizards.com/articles/features/elementalevil_playerscompanion) - All the spells referenced in the Elemental Evil adventure that weren't in the Basic rules, and a few new races.
* There are also supplements for [Hoard of the Dragon Queen](http://dnd.wizards.com/products/tabletop-games/rpg-products/hoard-dragon-queen), [Princes of the Apocalypse](http://dnd.wizards.com/products/tabletop-games/rpg-products/princes-apocalypse), and [Rise of Tiamat](http://dnd.wizards.com/products/tabletop-games/rpg-products/rise-tiamat) that detail all the spells, monsters, and magic items referenced in those adventures that weren't in the Basic rules.
(I have created [an index of all the above documents](http://www.enworld.org/forum/showthread.php?477146-The-Cheapskate-Index-An-index-to-WotC-s-free-PDFs) that you may find useful)
You may also be interested in the [Unearthed Arcana](http://dnd.wizards.com/search/site/unearthed%2520arcana) articles, that detail not-fully-tested options. These may or may not appear in later books, in modified form.
There are also 3rd-party supplements on the [Dungeonmasters Guild](http://www.dmsguild.com/browse.php?pto=0&pfrom=0), some of which are free. | As well as the free [Basic Rules](http://dnd.wizards.com/articles/features/basicrules), there are a number of online supplements, most of which contain monsters and magic items.
* [Hoard of the Dragon Queen](https://dnd.wizards.com/products/tabletop-games/rpg-products/hoard-dragon-queen)
* [The Rise of Tiamat](http://dnd.wizards.com/products/tabletop-games/rpg-products/rise-tiamat)
* [Princes of the Apocalypse](http://dnd.wizards.com/products/tabletop-games/rpg-products/princes-apocalypse)
I remember a thread a year or so ago where one of Wizard's staff said you can play the game by buying one book. I believe they suggested the Monster Manual. That is, use the free Basic Rules and the purchased MM. The idea was that reading the monster stats gave lots of cool ideas for adventures.
Personally, I think that buying the PHB is a no-brainer. The Basic rules only give you a few classes and archetypes; the PHB gives you all of them. Add the free Elemental Evil Player's Companion for a few more races and spells.
You may want to borrow the Sword Coast Adventurer's Guide before you read it. I'm hearing mixed reviews, and more than a few people are telling me not to waste money on it. YMMV.
I would also suggest [D&D Classics](http://www.dmsguild.com/browse.php?filters=45471_0_0_0_0_0). A few dollars there will get you old d&d adventures that work very well in 5th edition. I've found that 1st ed modules need very little conversion (just picking appropriate monsters for the party level). |
27,386 | What is the grammatical or syntax term for a *sentence structure* in which there are more than one subject or more than one object continuously in the sentence?
Example 1:
In this sentence, the there are three [**object**](https://dictionary.cambridge.org/grammar/british-grammar/about-words-clauses-and-sentences/objects)s.
>
> He studies **English, Spanish** and **Portuguese**.
>
>
>
Example 2:
In this example there are two subjects:
>
> **The boy and the girl** ate the food.
>
>
> | 2018/03/11 | [
"https://linguistics.stackexchange.com/questions/27386",
"https://linguistics.stackexchange.com",
"https://linguistics.stackexchange.com/users/12668/"
] | Not sure about how it is called in grammar of English, but "English, Spanish and Portuguese" is just the direct object, and "the boy and the girl" is just the subject. Each structure can be formed by more than one word and by more than one real world item. | It is called: **conjunction-reduction**.
In transformational grammar it is a rule that reduces coordinate sentences, applied, for example, to convert "*John **lives** in Ireland and Brian lives* in Ireland" into "*John and Brian **live** in Ireland*". ([Collins](https://www.collinsdictionary.com/dictionary/english/conjunction-reduction))
Credit: @jlawler in the comment. |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | You can still use the island metaphor.
If the defending planet is technologically advanced enough to have their own space force, then they could have a blockade of ships around the planet.
Your front line is the extent of gravitational reach of the planet, or even further away depending on how fast/powerful the ships are. You could even compare artillery hidden in a forest to fortifications hidden in a meteor field.
Retreating inward to the island would be entering the planet atmosphere to take up ground defenses or activate more powerful weapons which have limitations that prevent them from being placed in space. Your island defense warship might have a nice cannon, but typically you have a larger one on the island that just can't fit on the ship.
Invaders may also want to not obliterate the surface of the planet if there is a strategic or otherwise coveted resource which is rare among other planets. You may even want to leave a certain amount of infrastructure in tact to save costs of developing a way to harvest that resource.
So:
If you want to invade a planet, but don't care about it strategically, then you go for shock and awe. A space faring civilization could possibly build a massive bulky spacecraft to use as a metal asteroid and just accelerate it as much as possible to destroy or cripple the planet in one shot.
If you want to invade and keep things, then you might use more precise tactics such as disabling communications, defenses, etc. But you would be more careful about launching weapons that could obliterate an entire continent. You might even want to use ground forces if the defending side can destroy your larger vessels. Alllllsooooo, a massive ship might not want to enter the gravitational pull of a planet, because then they need to spend a lot of fuel to leave again.
If you are a defender, you would want to establish your front line. Have a standing military that can hold a line in space. Use natural satellites and debris to conceal long range artillery. Put long range sensors out in space to detect an incoming invasion force so that you have time to prepare. And of course, make sure you have larger defenses planet-side that you can use while your front line ships hold off the invading force. | Just as an alternative to the "there is something you want that you shouldnt destroy" idea, the available supplies could prevent this.
Lots of popular science fiction makes the space travel exceedingly simple and almost costless. Just set your location and you can get all the equipment you need to the planet in no time! But what if that isnt the case?
Imagine that you can only carry so much material to a planet. You can use a few kinetic bombardments but only to strike a few targets, its a stragetic weapon to damage key formations, not something to wipe a planet clean. Getting space rocks off-course into the planet/sun takes time, fuel and several space-battles as the planet's owners will send ships to try and get the rock on another course long before it even gets close.
So the attackers have come up with a different strategy: they arrive, use what KE bombardments with Rods From God and nukes to suppress and clear enemy prescenses near your landing zone where one or more ships will land. These ships are equipped with factories that will use the local materials to generate the equipment you need for the invasion (including perhaps 3D printed soldiers?). While you have control of space, you also have to capture an ENTIRE PLANET with the soldiers you brought with you. Likely a lot less people than the entire planet can throw at them. The invaders will need to capture more infrastructure and production facilities (likely something they try to land on top of) to succeed.
The defenders in the meantime will be building up their own forces and create missiles in secretive bunkers. Once enough missiles are created they will fire them simultaneously at any ships in the solar system. Encouraging the attackers to either hide their ships or land most of them on the planet to support the invasion instead of just nuking everything from orbit without resistance. |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | Well, part of the Island Hopping strategy had to deal with the fact that many the islands weren't lone chunks of land, but archipelago chains (Hawaii, the Philipines, Indonesia, Japan are all islands nations/states that include more than one Island... and were also part of the Pacific Theater). So many battles for one piece of territory were spread over multiple Islands... Perhaps use this to make your story... You're not invading a single enemy planet, but an enemy stellar system of planets. This allows for greater diversity. If we look at our own solar system we have the following areas:
Your shore waters would be your Kuiper Belt and Dwarf Planets/Plutoian celestial bodies... Here is where you should consider prepping your fleet for "landing" and taking interior planets. The defender would also likely station patrols and early warning systems here, so at this stage, both the defenses and offenses are have their red alerts and battle stations calls sounded and are mobilizing for battle.
Heading interior, our Gas giants would be our shore (Jupiter, Saturn, Uranus, Neptune). Each of theses are large planets with stormy atmospheres that would hide all manner of fun space station defenses and fleet depots to take. Additionally, all of those planets have multiple moons and plantary rings that can have some fun counter invasion measures. Your radar stations, fuel, scrambled star fighters, gun boats, and other defenses.
Our Asteroid Belt would be the demarkation of the forest line or other change from beach to interior land, and finally the rocky planets and the star (Sun, Mercury, Venus, Earth, Mars) would be the interior of an island. This isn't unheard of as anyone defending a planet in intersteller war will likely have resources spread out into the solar system to stop the advancing ships.... your big ships aren't just the fleet, but the tanks in this scenario.
YOu can see models like this in fiction like Star Trek, where the Solar system does have multiple facilities on other planets that all count to the defense of the Solar system. Headquarters is on Earth, but repair facilities are on Mars, with Jupiter serving as a command center for system movement, coordinating early warning, clearances to enter and leave Earth, and having an air field that can launch patrol fighter shuttles and other equipment. Each of these have ground and space based stations that also have roles to play. While the canon was that Earth was to well defended for a surprise strike, in the show the Dominion pulled it off for a moral victory in DS9 and in Star Trek Online, one of the Klingon missions has you lead a raid on military facilities that end up in a Pearl Harbor like action (basically you blow up ship yards on Mars, crippling repair facilities).
Now, how do we organize this invasion. All ships in a fleet are organized into "Groups". A command structure from the top would be a high ranking Admiral in charge of both the Fleet and lower ranking Admirals in charge of a single group...
What required ships for a group largely depends on your group organization theory and your mission needs... typically, the Group will be the Capital Ship and it's screen ships. Your Capital ship is your big offensive weapon and your screen protects the capital ship so it doesn't have to play defense. World War II is unique in that two different schools of capital ship theory were in different points of their life span: Battleship Theory was on it's way to being phased out, while Carrier Theory was the young hot newness of Naval Combat. Which ever theory you want to go with, keep in mind that the Capital Ship is the offensive ship, and the other ships are making sure that it doesn't die.
In real naval combat, Carrier theory is far superior as it's weapons systems (the planes) are able to better target enemies and from a father range. The Battle of Midway, which was the first true carrier to carrier naval battle, was fought without either side's ship coming within visual range of each other and was fought mostly this way because the U.S. Battle Ships were still recovering from Pearl Harbor and the Japanese developed Carriers to get around crippling restrictions on Battleships that had been placed on it (treaties on Capital ship limitations at the time were written when Carriers were first being tested as a concept at all). Battleship theory has a shorter range but was still used for support of landing forces and while it wasn't accurate, they didn't need to be... those shells still could reach targets out of line of sight and didn't need to hit directly... close was good enough to work.
In Sci-Fi a good Carrier vs. Battleship demonstration is to look at how Star Wars and Star Trek fight ship to ship in space battles. Star Wars uses Carrier Theory as the Star Destroyers (and their prequel sister classes more so) would deploy small fighters and smaller ships that couldn't be targeted by the big guns to fly close and shoot ships. Return of the Jedi has a great "group" mechanic employed where the Capital Ship (Death Star II) has a protective screen of Cruisers (Super Star Destroyers) and Destroyers (Star Destroyers) as well as fighter aircraft (TIE fighters) all engaging the enemy fleet... to the point that for much of the battle, the Death Star II was largely not focused on the battle and it's weapons were actually pretty spot on for its role. As a Carrier, it was much more sucessful as the fighters can be used for offense or defense, while as a Destroyer, the Planet-Blow-Up-Ray was largely scary but ineffective at close ranges. Star Trek is noted for it's lack of carrier ships on screen with the Enterprise almost always being a ship akin to a Battleship (and occasionally submarines, given the nature of both being boats surrounded by hostile environment). Almost any ship to ship engagement is sure to be broadsides with lasers, which suits battleship theory, and the shuttle compliments are never used in engagements. Deep Space 9, which shows fleet actions actually uprooted it completely by using organizations that would be based off of air-force operations, not naval operations (Sisko would repeated call out to "wings" instead of "groups" in the multiship battles).
A typical Carrier "Group" (which in the modern world, is enough) is usually alone and rarely works in a fleet. The United States is the only nation at time of writing with more than 2 carriers... 11 to be exact... and that's only counting the 11 Nimitz and Ford class super-carriers... the American Class "Amphibious Assault" ships aren't "Carriers" in U.S. Navy terms, even though they are bigger than most non-U.S. carriers and allow for air craft to take off and land from them... which is all you need for carriers to be counted as such... The U.S. has 20 of these). Typically the command of the group will be under a Rear Admiral Lower Half. On the carrier, there would be two people of Captain Rank running the shows. The Captain, who is incharge of the ship's operations and the CAG (never addressed as Captain while Underway... Ships have one Captain... his proper rank is Captain though) who is in charge of the ship's Air Wing (in the Navy, a Wing of airplanes is considered a "ship" for the purposes of Command). The Rear Admiral is also in charge of the Groups Cruiser Captains (Usually two, but numbers may differ for mission), the Destroyer Group Captain (all destroyers have a single Captain in charge, but if he or she is on another ship, the CO on your ship is usually a Commander) and the submarine commanders (Submarines usually have a CO of Commander Rank... they also are not ships, but boats... don't ask me why but never call a ship a boat or a boat a ship... it's insulting, for reasons...). If there are two "groups" in a single battle, typically the Admiral might be higher rank (Rear Admiral Upper Half or Vice Admiral) but will be dual hatted with both Group commander and fleet commander... this is because while any capital ships will have space for the Admiral's staff to due their job, they don't have duplicate space. In a carrier's "Island" there are three general levels for each CO onboard. Captain has the Bridge, CAG has the tower control, and Admiral has a level for general coordination between all ships. Battle ships similarly have a bridge and CIC (in the interior of the ship) to handle communications and multi-ship coordination. Also there is a difference between a Capital Ship and a Flag Ship. A Capital Ship is typically the ship with the most firepower while the Flag Ship is the ship with the Admiral on it (Admirals have individual flags that they are authorized to fly on their ship, hence the name. In the Days of Semaphore, this was needed so Captains could readily identify which ship was giving orders). So if the Admiral decides to run his show out of a Cruiser's CIC, then the Cruiser is the Flag Ship, but the Carrier is the Capital Ship.
In space combat, Battleship theory is a bit more viable if you're going to try for realistic, as the guns in space can have the same range as fighers without having the worry of pilots... And actually, a good portrayal would be using Submarine warfare if you go that route as subs rarely engage targets with a visual contact. On scree, this is boring unless you use the silent hunting for drama (Wrath of Khan does this wonderfully, as does the TOS episode with the first appearance of the Romulans). DS9 often used the Defiant's stripped down and limited space status (and cloaking device) to do sub stories in Space. This also works as Subs fight in 3D spaces as a space ship would, where as surface ships fight on a 2D plane (Wrath of Khan also uses this to allow Kirk to get the upper hand on Khan, who is a brilliant commander from his grasp of surface naval warfare... he doesn't think of space as 3D).
Other options are to make a capital ship a Battlestar (from the series of Battlestar Galactica, the titualar ships are Hybrid Carrier/Battleships. These don't work in navies but the contained flight deck of many space carriers means all the guns of a battleship be viable. Carriers don't have many guns as they can't be fired while in launch or recovery of aircraft... which is kinda the point of making a carrier anyway). Typically space carriers will have the flight deck embedded into the belly of the ship, either running stern to bow or port to starboard or off to the sides like wings. Each have an advantage over the real carrier as Launch and Recovery can happen simultaneously. In the latter two options, multiple runways exist, and one is dedicated to take off and one to landing. In the former, the flight deck is so long, it can do both.
As for ground landings, there isn't a lot as most scifi send woefully underwelming man power to planetary invasions... something akin to Helicopter Transport of Marines from ship to shore is generally depicted (consider those really cool looking landing craft in the Clone Wars finale). Star Trek rarely dealt with on screen ground depictions, though they did say they happened. Part of the reason is the book Starship: Trooper is such a big scifi staple that it tends to be dominant for overall planet wide theaters and it's difficult to show a planet wide scope of ground battle. Starship: Troopers is told from a Marine ground combatant and the military employs power armor for it's infantry. The book does describe that a single individual infantry man can typically cover a staggering amount of terrain by himself... at one point the hero notes that a unit formation with individuals spaced a kilometer apart is a very unusually tight formation that presents a threat of friendly fire from being clustered so close. | It depends on if you want the planet intact. If you want to leave things intact for your usage, especially their infrastructure, then unless you want to destroy some of it to cripple them a la WWII Allied bombings of German railways, you still have to invade on the ground and fight a conventional war. This lets you use the area as either a colony or, if you don't kill everyone, a slave colony, and use the resources potentially more efficiently (at least cheaply) than if you had to transport your own equipment.
If you only want resources, then you can destroy their main urban areas and send down your own harvesting equipment to the areas with the resources, a la *Halo*. Because planetary natives are secondary to your alien's goals, they can be killed off indiscriminately while they look for resources. Once the resources are located and collected, then the planet can be destroyed so other aliens can't use it. |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | ### The defense: An array of really big satellite turrets.
Our current technology has no effective means of fighting off an attack from space, but unless we are talking about an invasion from a vastly technologically superior species we can presume that as spacecraft technology advanced, so did the defenses needed to defend against those spacecraft.
The first use of aircraft in warfare had no effective defenses, but anti-aircraft artillery quickly evolved to shoot down incoming planes. What we need, then, is anti-spacecraft guns - preferably positioned in orbit.
The key technology necessary for defending against an interplanetary invasion is a really long-ranged gun capable of hitting anything within a large, spherical region - anywhere it is not blocked by the planet itself. This will allow you to set up a defensive array with a relatively small number of satellites. The key to invading a planet, therefore, will be to either destroy one or more of these satellites or sneak past them.
### The invasion: a Trojan Horse.
Since there is No Stealth In Space, if you intend to sneak past these satellites the only way to do so will be to pose as something you're not - sneak a bunch of soldiers inside what appears to be a group of benign cargo ships, for instance. This will, naturally, limit the number of troops you can field and the places you can field them.
The objective of the invasion will not be to conquer the planet's surface with infantry, but to take control of the base or bases that control the Planetary Defense Array. Once the satellites are down, the planet will be vulnerable to space invasion, rendering it effectively defenseless.
If you have warp gate technology, the initial invaders could set up a portal on the ground, allowing you to field more troops but restricting their entry point, forcing you to use more conventional ground-based strategy. | I'll summarize vastly different invasion strategies from different SF novels (Many details will be wrong because it's so long ago I read those).
**Iain M Banks - The Algebraist:** In this space opera, a warlord travels, with a huge fleet to a system to embiggen his empire and go after a Mc Guffin that's hidden somehwere there. His strategy is to achieve space dominance (it's pretty much a curb stomp battle), the threaten the system governemnt into submission by destroying habitats, murdering millions. IIRC, the actual planetary invasion happens afterwards, to secure important points on the main inhabited planet. OP is to clear a landing zone with neutron bombs, land power armored troops with vast air superiority - but these only have to deal with isolated resistance nests (and the fact that *some* aliens that coinhabit the invaded system, and are part of its military, are more radiation resistant than humans ...).
The drives of the invading fleet show up on the night sky as hundred extra stars as they break from relativistic speeds (the parts that don't fly through the system *at* relativistic speeds, taking potshots at military targets). Some, especially those with much to loose, offer tehir support to the new overlords.
Meanwhile, a smaller but technologically more advanced fleet is on it's way to fight the invaders (but will be late to the party). Part of *their* stated strategy is punitive measures against the population and elite of the system, if tehy find the resistance lacking.
**Charles Stross - Singularity Sky:** An interstellar expedition of post scarcity, post singularity (and post human) civilization comes across a planet whose population is mostly held at mid 20th century level by their dictatorship. The "invaders" are not interested in material goods, they care for interesting ideas, culture, and people to upload into their simulated world n their ship. Their invasion starts with a rain of mobile telefones. Place a call, take to the invaders, make a wish ...
**Stanisław Lem - Fiasco** is not about an invasion at all. The human explorers want to make peaceful contact. Their attempts at communication are met with silence, the strategy of the explorers is to communicate unambigously (using a powerful laser to write into clouds) and make credible threats (IIRC they blow up a moon) to force contact and communication. The title of the book is somehwat of a spoiler, but it's a good read.
**Iain M Banks - Consider Phlebas** features planetary invasions as a background event. The Idirans (the civilization taht does the invading) are technologically advanced enough to live a post scarcity life or live in space entirely. They chose not to, the strategy seems to rely on total space dominance, well armed shock troops and local collaborators.
**Arkady and Boris Strugatzky - Wayside Picknick** No invasion, but a contact with aliens that turns some areas of the world into zones filled with deadly traps, weird phenomena and some trinkets. Noone knows what the goal of the aliens was, maybe it *was* just a wayside picknick. No discernible strategy, several points on the globe ar hit by something resembling meteor strikes. That's it.
**unkown** One recentish "invasion" story - I forgot the author and name of the story - has aline nanotech somethings land in Kenya. The somethings build weird structures, change the landscape and are dangerous to touch. This leads to efforts to research them, plunder parts (similar to wayside picknick, except the zone is expanding). |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | Here is my take on this.
Moving up/ down from a gravity well is expensive, slow, and prone to catastrophic failure.
Luckily we have space elevators (more realistically space rings) that allow us to use the power of the sun to lift things too/from the surface of the planet, instead of wasteing the unobtanium that powers our handwavium drive.
Space elevators are extremely expensive to build, it's a megastructrue. Not something you would destroy out of hand. As not having a space elevator makes the planet worthless for both the invader and the defender. Therefore neither side wants to destroy the space elevator.
Invasions would start out with odsts falling from the sky to secure the base of a space elevator. While marines capture the official super structure.
The landing point than becomes your primary beach head as it is drastically cheaper to get supplies planetside thru the elevator than a hot drop.
But why don't you just glass the planet? Or use bio weapons to clear out the unwanted population?
The solution is that this was done in the past, leaving behind tomb worlds and the shattered husks of planets. The civilized species got together in a galactic convention and decided to lay out the rules of war they expect everyone to follow
Breaking this convention, will lead to all other civilized species declaring war on you. Not something you want. | Just as an alternative to the "there is something you want that you shouldnt destroy" idea, the available supplies could prevent this.
Lots of popular science fiction makes the space travel exceedingly simple and almost costless. Just set your location and you can get all the equipment you need to the planet in no time! But what if that isnt the case?
Imagine that you can only carry so much material to a planet. You can use a few kinetic bombardments but only to strike a few targets, its a stragetic weapon to damage key formations, not something to wipe a planet clean. Getting space rocks off-course into the planet/sun takes time, fuel and several space-battles as the planet's owners will send ships to try and get the rock on another course long before it even gets close.
So the attackers have come up with a different strategy: they arrive, use what KE bombardments with Rods From God and nukes to suppress and clear enemy prescenses near your landing zone where one or more ships will land. These ships are equipped with factories that will use the local materials to generate the equipment you need for the invasion (including perhaps 3D printed soldiers?). While you have control of space, you also have to capture an ENTIRE PLANET with the soldiers you brought with you. Likely a lot less people than the entire planet can throw at them. The invaders will need to capture more infrastructure and production facilities (likely something they try to land on top of) to succeed.
The defenders in the meantime will be building up their own forces and create missiles in secretive bunkers. Once enough missiles are created they will fire them simultaneously at any ships in the solar system. Encouraging the attackers to either hide their ships or land most of them on the planet to support the invasion instead of just nuking everything from orbit without resistance. |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | Phil Geusz's David Birkenhead series has one of these that works.
The background is that there's a civil war in an interplanetary empire, and this planet was planning to switch from the loyalists to the rebels. The loyalists arrived first and prevented the betrayal, so the rebels arrive to find a planet against them instead of for them. The rebels have to take the planet, or their massive fleet will run dry. The book goes into plenty of depth about the fighting that results, which, roughly speaking, takes the following shape.
First, there's some fighting in space, which the rebels easily win. Then, the rebels make a few landing attempts; the first is ambushed right after landing and heavily defeated, but the second is successful. The rebels then land a large force on the planet, occupying its cities, but a massive planetwide guerilla war combined with sabotage operations prior to the rebel landing prevent total occupation. The rebel fleet is stuck waiting, which allows the main loyalist fleet to arrive and defeat the weakened rebel fleet.
To answer your question, the purpose here was simple - the planet had supplies that the rebel fleet needed in order to function. Necessity of supplies has been one of the biggest factors in warfare throughout history, and that wouldn't change in the future, short of replicators being invented.
(The series in general has one of the most realistic strategic representations of space warfare I've ever seen. It talks about the problems of defending such a large body as a planet, commerce raiding, psychological warfare, and more.) | **TL;DR**
Well, the thing is, you can't invade earth, as we have enough firepower to blast any fleet that comes withing range.\* Therefore, your aliens must consider alternative options. A viable strategy for them would be to show up in orbit with a mock-up of the Death Star in tow.
---
**Long answer:**
While it would be very easy to get ships to a planet you want to invade, and you could land troops pretty easily, it would be hard to maintain the beachhead. You see, while there would be quite a bit of confusion during the initial landing, governments would quickly get their collective acts together enough to drop a [Tsar Bomba](https://en.wikipedia.org/wiki/Tsar_Bomba), killing anybody unfortunate enough to be in the area. If you try to land elsewhere, they will do it again as many times as necessary. Landing in multiple spots would not fix the problem, as then the earthlings would just use a bunch of smaller nukes (or a few MOABs.)
Destroying bombers / missiles before they reach your troops would not solve this problem, as then militaries would bring weapons like the [M65 "Atomic Annie",](https://en.wikipedia.org/wiki/M65_atomic_cannon) point defense systems being useless against these.
While your troops are being destroyed on the ground, your fleet is experiencing similar problems. For the first 30 minutes they will be safe, no problems. Minute 31 is when the fireworks start. Missile silos throughout the world will pour forth their deadly contents, they being so profuse and of such diverse types that even the best point defenses will be unable to block all of them. Even if your forces manage to destroy the missile silos in time (unlikely; they are usually well hidden) they will still have to deal with all the missiles being fired from submarines and single-rocket launch points. Regardless, 15 minutes after the missiles are launched they will reach your fleet.
***45 minutes after your fleet drops out of FTL it will be destroyed.***
Because of these problems, **your empire will have to explore other options.**
The first (and least risky) is to take the route of the [Pierson's Puppeteers](https://en.wikipedia.org/wiki/Pierson%27s_Puppeteers) from Larry Niven's *Known Space* series. In other words, instead of wasting time on bootless attacks, just use trade and governmental corruption to bend them to your will. For example, in the novel *Ringworld*, a Puppeteer named Nessus admits that the Puppeteers manipulated the Humans and Kzinti into engaging in four extremely bloody wars with each other. This had the net effect of killing most of the Kzinti, making them less of a threat for the Puppeteers.
If your hypothetical race is willing to wait a few millenia, they could just nuke the planet. This would kill everything, meaning no resistance. Of course though, it would also make the planet unusable for a few millenia before they can terraform it, but such concerns are relatively minor...
If they are *not* willing to wait, they could always go with the approach that @M.A.Golding suggested, namely by appearing in orbit with a mock-up of the Death Star and then broadcasting a message to the effect of "Greetings Earthlings! You will be pleased to learn that the total extermination of your species can still be avoided by total surrender if done quickly enough." That being said, this would be a *very* risky approach, as the Earth governments would probably respond by painting "Bug off!" on the nosecones of their missiles before launching them.
\*Nota Bene: Unlike what they show in Stargate: SG1, an energy field would be unable to mitigate the shockwave or radiation from a nuclear weapon. |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | Well, part of the Island Hopping strategy had to deal with the fact that many the islands weren't lone chunks of land, but archipelago chains (Hawaii, the Philipines, Indonesia, Japan are all islands nations/states that include more than one Island... and were also part of the Pacific Theater). So many battles for one piece of territory were spread over multiple Islands... Perhaps use this to make your story... You're not invading a single enemy planet, but an enemy stellar system of planets. This allows for greater diversity. If we look at our own solar system we have the following areas:
Your shore waters would be your Kuiper Belt and Dwarf Planets/Plutoian celestial bodies... Here is where you should consider prepping your fleet for "landing" and taking interior planets. The defender would also likely station patrols and early warning systems here, so at this stage, both the defenses and offenses are have their red alerts and battle stations calls sounded and are mobilizing for battle.
Heading interior, our Gas giants would be our shore (Jupiter, Saturn, Uranus, Neptune). Each of theses are large planets with stormy atmospheres that would hide all manner of fun space station defenses and fleet depots to take. Additionally, all of those planets have multiple moons and plantary rings that can have some fun counter invasion measures. Your radar stations, fuel, scrambled star fighters, gun boats, and other defenses.
Our Asteroid Belt would be the demarkation of the forest line or other change from beach to interior land, and finally the rocky planets and the star (Sun, Mercury, Venus, Earth, Mars) would be the interior of an island. This isn't unheard of as anyone defending a planet in intersteller war will likely have resources spread out into the solar system to stop the advancing ships.... your big ships aren't just the fleet, but the tanks in this scenario.
YOu can see models like this in fiction like Star Trek, where the Solar system does have multiple facilities on other planets that all count to the defense of the Solar system. Headquarters is on Earth, but repair facilities are on Mars, with Jupiter serving as a command center for system movement, coordinating early warning, clearances to enter and leave Earth, and having an air field that can launch patrol fighter shuttles and other equipment. Each of these have ground and space based stations that also have roles to play. While the canon was that Earth was to well defended for a surprise strike, in the show the Dominion pulled it off for a moral victory in DS9 and in Star Trek Online, one of the Klingon missions has you lead a raid on military facilities that end up in a Pearl Harbor like action (basically you blow up ship yards on Mars, crippling repair facilities).
Now, how do we organize this invasion. All ships in a fleet are organized into "Groups". A command structure from the top would be a high ranking Admiral in charge of both the Fleet and lower ranking Admirals in charge of a single group...
What required ships for a group largely depends on your group organization theory and your mission needs... typically, the Group will be the Capital Ship and it's screen ships. Your Capital ship is your big offensive weapon and your screen protects the capital ship so it doesn't have to play defense. World War II is unique in that two different schools of capital ship theory were in different points of their life span: Battleship Theory was on it's way to being phased out, while Carrier Theory was the young hot newness of Naval Combat. Which ever theory you want to go with, keep in mind that the Capital Ship is the offensive ship, and the other ships are making sure that it doesn't die.
In real naval combat, Carrier theory is far superior as it's weapons systems (the planes) are able to better target enemies and from a father range. The Battle of Midway, which was the first true carrier to carrier naval battle, was fought without either side's ship coming within visual range of each other and was fought mostly this way because the U.S. Battle Ships were still recovering from Pearl Harbor and the Japanese developed Carriers to get around crippling restrictions on Battleships that had been placed on it (treaties on Capital ship limitations at the time were written when Carriers were first being tested as a concept at all). Battleship theory has a shorter range but was still used for support of landing forces and while it wasn't accurate, they didn't need to be... those shells still could reach targets out of line of sight and didn't need to hit directly... close was good enough to work.
In Sci-Fi a good Carrier vs. Battleship demonstration is to look at how Star Wars and Star Trek fight ship to ship in space battles. Star Wars uses Carrier Theory as the Star Destroyers (and their prequel sister classes more so) would deploy small fighters and smaller ships that couldn't be targeted by the big guns to fly close and shoot ships. Return of the Jedi has a great "group" mechanic employed where the Capital Ship (Death Star II) has a protective screen of Cruisers (Super Star Destroyers) and Destroyers (Star Destroyers) as well as fighter aircraft (TIE fighters) all engaging the enemy fleet... to the point that for much of the battle, the Death Star II was largely not focused on the battle and it's weapons were actually pretty spot on for its role. As a Carrier, it was much more sucessful as the fighters can be used for offense or defense, while as a Destroyer, the Planet-Blow-Up-Ray was largely scary but ineffective at close ranges. Star Trek is noted for it's lack of carrier ships on screen with the Enterprise almost always being a ship akin to a Battleship (and occasionally submarines, given the nature of both being boats surrounded by hostile environment). Almost any ship to ship engagement is sure to be broadsides with lasers, which suits battleship theory, and the shuttle compliments are never used in engagements. Deep Space 9, which shows fleet actions actually uprooted it completely by using organizations that would be based off of air-force operations, not naval operations (Sisko would repeated call out to "wings" instead of "groups" in the multiship battles).
A typical Carrier "Group" (which in the modern world, is enough) is usually alone and rarely works in a fleet. The United States is the only nation at time of writing with more than 2 carriers... 11 to be exact... and that's only counting the 11 Nimitz and Ford class super-carriers... the American Class "Amphibious Assault" ships aren't "Carriers" in U.S. Navy terms, even though they are bigger than most non-U.S. carriers and allow for air craft to take off and land from them... which is all you need for carriers to be counted as such... The U.S. has 20 of these). Typically the command of the group will be under a Rear Admiral Lower Half. On the carrier, there would be two people of Captain Rank running the shows. The Captain, who is incharge of the ship's operations and the CAG (never addressed as Captain while Underway... Ships have one Captain... his proper rank is Captain though) who is in charge of the ship's Air Wing (in the Navy, a Wing of airplanes is considered a "ship" for the purposes of Command). The Rear Admiral is also in charge of the Groups Cruiser Captains (Usually two, but numbers may differ for mission), the Destroyer Group Captain (all destroyers have a single Captain in charge, but if he or she is on another ship, the CO on your ship is usually a Commander) and the submarine commanders (Submarines usually have a CO of Commander Rank... they also are not ships, but boats... don't ask me why but never call a ship a boat or a boat a ship... it's insulting, for reasons...). If there are two "groups" in a single battle, typically the Admiral might be higher rank (Rear Admiral Upper Half or Vice Admiral) but will be dual hatted with both Group commander and fleet commander... this is because while any capital ships will have space for the Admiral's staff to due their job, they don't have duplicate space. In a carrier's "Island" there are three general levels for each CO onboard. Captain has the Bridge, CAG has the tower control, and Admiral has a level for general coordination between all ships. Battle ships similarly have a bridge and CIC (in the interior of the ship) to handle communications and multi-ship coordination. Also there is a difference between a Capital Ship and a Flag Ship. A Capital Ship is typically the ship with the most firepower while the Flag Ship is the ship with the Admiral on it (Admirals have individual flags that they are authorized to fly on their ship, hence the name. In the Days of Semaphore, this was needed so Captains could readily identify which ship was giving orders). So if the Admiral decides to run his show out of a Cruiser's CIC, then the Cruiser is the Flag Ship, but the Carrier is the Capital Ship.
In space combat, Battleship theory is a bit more viable if you're going to try for realistic, as the guns in space can have the same range as fighers without having the worry of pilots... And actually, a good portrayal would be using Submarine warfare if you go that route as subs rarely engage targets with a visual contact. On scree, this is boring unless you use the silent hunting for drama (Wrath of Khan does this wonderfully, as does the TOS episode with the first appearance of the Romulans). DS9 often used the Defiant's stripped down and limited space status (and cloaking device) to do sub stories in Space. This also works as Subs fight in 3D spaces as a space ship would, where as surface ships fight on a 2D plane (Wrath of Khan also uses this to allow Kirk to get the upper hand on Khan, who is a brilliant commander from his grasp of surface naval warfare... he doesn't think of space as 3D).
Other options are to make a capital ship a Battlestar (from the series of Battlestar Galactica, the titualar ships are Hybrid Carrier/Battleships. These don't work in navies but the contained flight deck of many space carriers means all the guns of a battleship be viable. Carriers don't have many guns as they can't be fired while in launch or recovery of aircraft... which is kinda the point of making a carrier anyway). Typically space carriers will have the flight deck embedded into the belly of the ship, either running stern to bow or port to starboard or off to the sides like wings. Each have an advantage over the real carrier as Launch and Recovery can happen simultaneously. In the latter two options, multiple runways exist, and one is dedicated to take off and one to landing. In the former, the flight deck is so long, it can do both.
As for ground landings, there isn't a lot as most scifi send woefully underwelming man power to planetary invasions... something akin to Helicopter Transport of Marines from ship to shore is generally depicted (consider those really cool looking landing craft in the Clone Wars finale). Star Trek rarely dealt with on screen ground depictions, though they did say they happened. Part of the reason is the book Starship: Trooper is such a big scifi staple that it tends to be dominant for overall planet wide theaters and it's difficult to show a planet wide scope of ground battle. Starship: Troopers is told from a Marine ground combatant and the military employs power armor for it's infantry. The book does describe that a single individual infantry man can typically cover a staggering amount of terrain by himself... at one point the hero notes that a unit formation with individuals spaced a kilometer apart is a very unusually tight formation that presents a threat of friendly fire from being clustered so close. | Just as an alternative to the "there is something you want that you shouldnt destroy" idea, the available supplies could prevent this.
Lots of popular science fiction makes the space travel exceedingly simple and almost costless. Just set your location and you can get all the equipment you need to the planet in no time! But what if that isnt the case?
Imagine that you can only carry so much material to a planet. You can use a few kinetic bombardments but only to strike a few targets, its a stragetic weapon to damage key formations, not something to wipe a planet clean. Getting space rocks off-course into the planet/sun takes time, fuel and several space-battles as the planet's owners will send ships to try and get the rock on another course long before it even gets close.
So the attackers have come up with a different strategy: they arrive, use what KE bombardments with Rods From God and nukes to suppress and clear enemy prescenses near your landing zone where one or more ships will land. These ships are equipped with factories that will use the local materials to generate the equipment you need for the invasion (including perhaps 3D printed soldiers?). While you have control of space, you also have to capture an ENTIRE PLANET with the soldiers you brought with you. Likely a lot less people than the entire planet can throw at them. The invaders will need to capture more infrastructure and production facilities (likely something they try to land on top of) to succeed.
The defenders in the meantime will be building up their own forces and create missiles in secretive bunkers. Once enough missiles are created they will fire them simultaneously at any ships in the solar system. Encouraging the attackers to either hide their ships or land most of them on the planet to support the invasion instead of just nuking everything from orbit without resistance. |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | >
> why invade at all? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above.
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But you might not want to blast them from orbit because these items might also be of value to *you*.
You might want to avoid damage to the economic infrastructure. Economic assets like factories, resource stockpiles, mining facilities, research labs or transportation infrastructure could be useful for your own empire. You also might want to avoid excessive casualties among the civilian population. Either because you care about public opinion or because you have plans with the population which require them to be alive (for example: enslave, liberate, study, ritually sacrifice, re-educate, economically exploit or eat them).
So if you don't just want to take control of the planet but also of the assets on the surface, then you need troops on the ground.
So the average planetary invasion would likely work as follows:
1. Enter the solar system with your space fleet and neutralize any enemy forces in space (enemy fleets and armed space stations)
2. Enter orbit around the target planet. At that point, any mobile defending troops will likely start to entrench themselves in those areas they know you want to capture intact.
3. Neutralize any ground-to-orbit weapon systems which threaten your fleet in orbit.
4. Neutralize any military targets from orbit which you can safely destroy without hitting valuable assets. Barracks, government districts, military spaceports, ground troops which are still on the move, military production facilities.
5. If there are military assets you can not safely engage from orbit but which you want gone before you start the invasion, deploy aerodynamic precision bombers into the atmosphere to take them out or land small squads of special forces to perform surgical sabotage operations.
6. Land the bulk of your ground troops in areas which you believe to have minimum enemy presence and establish operating bases. Even though you can move troops quickly with space ships, having a permanent presence on the ground can be useful:
* You establish permanent hold over the surrounding area.
* Ground fortifications might make it harder for the enemy to attack back.
* You have a place ground troops can retreat to on their own in case you ever temporary lose air superiority.
* You have a place aerodynamic vessels can operate from.
* Your logistics, maintenance and medical personnel might have an easier time doing their job if they work in spacious ground facilities instead from inside a cramped space ship.
* Depending on how space ships work in your universe, landing from and launching to orbit might be costly, so you might want to limit such trips to a minimum.
7. Originating from those bases, have your ground troops conquer the population centers one by one. When your ground troops encounter resistance from entrenched enemies, aerial and orbital bombardments *might* be used as the situation allows.
But all of this of course assumes that you actually want the planet intact. If you simply want to obliterate your enemies, then you can just nuke the planet from orbit. | Phil Geusz's David Birkenhead series has one of these that works.
The background is that there's a civil war in an interplanetary empire, and this planet was planning to switch from the loyalists to the rebels. The loyalists arrived first and prevented the betrayal, so the rebels arrive to find a planet against them instead of for them. The rebels have to take the planet, or their massive fleet will run dry. The book goes into plenty of depth about the fighting that results, which, roughly speaking, takes the following shape.
First, there's some fighting in space, which the rebels easily win. Then, the rebels make a few landing attempts; the first is ambushed right after landing and heavily defeated, but the second is successful. The rebels then land a large force on the planet, occupying its cities, but a massive planetwide guerilla war combined with sabotage operations prior to the rebel landing prevent total occupation. The rebel fleet is stuck waiting, which allows the main loyalist fleet to arrive and defeat the weakened rebel fleet.
To answer your question, the purpose here was simple - the planet had supplies that the rebel fleet needed in order to function. Necessity of supplies has been one of the biggest factors in warfare throughout history, and that wouldn't change in the future, short of replicators being invented.
(The series in general has one of the most realistic strategic representations of space warfare I've ever seen. It talks about the problems of defending such a large body as a planet, commerce raiding, psychological warfare, and more.) |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | **They want the planet whole**
If they just wipe out huge chunks, humans will use nukes. If they capture the planet whole and the civilian population continues under occupation, they would be less likely to use scorched earth tactics.
A planet capable of supporting life isn't likely to be that common so to have the natives turn it into a radioactive cinder would be a tragedy. If you can capture the civilians, they won't want to nuke their own cities when you have seven billion hostages.
Once quelled, you can exterminate the lot but they need to believe they can surrender and live in peace until that point.
It means hand to hand fighting but a life supporting planet is worth the effort. | You can still use the island metaphor.
If the defending planet is technologically advanced enough to have their own space force, then they could have a blockade of ships around the planet.
Your front line is the extent of gravitational reach of the planet, or even further away depending on how fast/powerful the ships are. You could even compare artillery hidden in a forest to fortifications hidden in a meteor field.
Retreating inward to the island would be entering the planet atmosphere to take up ground defenses or activate more powerful weapons which have limitations that prevent them from being placed in space. Your island defense warship might have a nice cannon, but typically you have a larger one on the island that just can't fit on the ship.
Invaders may also want to not obliterate the surface of the planet if there is a strategic or otherwise coveted resource which is rare among other planets. You may even want to leave a certain amount of infrastructure in tact to save costs of developing a way to harvest that resource.
So:
If you want to invade a planet, but don't care about it strategically, then you go for shock and awe. A space faring civilization could possibly build a massive bulky spacecraft to use as a metal asteroid and just accelerate it as much as possible to destroy or cripple the planet in one shot.
If you want to invade and keep things, then you might use more precise tactics such as disabling communications, defenses, etc. But you would be more careful about launching weapons that could obliterate an entire continent. You might even want to use ground forces if the defending side can destroy your larger vessels. Alllllsooooo, a massive ship might not want to enter the gravitational pull of a planet, because then they need to spend a lot of fuel to leave again.
If you are a defender, you would want to establish your front line. Have a standing military that can hold a line in space. Use natural satellites and debris to conceal long range artillery. Put long range sensors out in space to detect an incoming invasion force so that you have time to prepare. And of course, make sure you have larger defenses planet-side that you can use while your front line ships hold off the invading force. |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | I'll summarize vastly different invasion strategies from different SF novels (Many details will be wrong because it's so long ago I read those).
**Iain M Banks - The Algebraist:** In this space opera, a warlord travels, with a huge fleet to a system to embiggen his empire and go after a Mc Guffin that's hidden somehwere there. His strategy is to achieve space dominance (it's pretty much a curb stomp battle), the threaten the system governemnt into submission by destroying habitats, murdering millions. IIRC, the actual planetary invasion happens afterwards, to secure important points on the main inhabited planet. OP is to clear a landing zone with neutron bombs, land power armored troops with vast air superiority - but these only have to deal with isolated resistance nests (and the fact that *some* aliens that coinhabit the invaded system, and are part of its military, are more radiation resistant than humans ...).
The drives of the invading fleet show up on the night sky as hundred extra stars as they break from relativistic speeds (the parts that don't fly through the system *at* relativistic speeds, taking potshots at military targets). Some, especially those with much to loose, offer tehir support to the new overlords.
Meanwhile, a smaller but technologically more advanced fleet is on it's way to fight the invaders (but will be late to the party). Part of *their* stated strategy is punitive measures against the population and elite of the system, if tehy find the resistance lacking.
**Charles Stross - Singularity Sky:** An interstellar expedition of post scarcity, post singularity (and post human) civilization comes across a planet whose population is mostly held at mid 20th century level by their dictatorship. The "invaders" are not interested in material goods, they care for interesting ideas, culture, and people to upload into their simulated world n their ship. Their invasion starts with a rain of mobile telefones. Place a call, take to the invaders, make a wish ...
**Stanisław Lem - Fiasco** is not about an invasion at all. The human explorers want to make peaceful contact. Their attempts at communication are met with silence, the strategy of the explorers is to communicate unambigously (using a powerful laser to write into clouds) and make credible threats (IIRC they blow up a moon) to force contact and communication. The title of the book is somehwat of a spoiler, but it's a good read.
**Iain M Banks - Consider Phlebas** features planetary invasions as a background event. The Idirans (the civilization taht does the invading) are technologically advanced enough to live a post scarcity life or live in space entirely. They chose not to, the strategy seems to rely on total space dominance, well armed shock troops and local collaborators.
**Arkady and Boris Strugatzky - Wayside Picknick** No invasion, but a contact with aliens that turns some areas of the world into zones filled with deadly traps, weird phenomena and some trinkets. Noone knows what the goal of the aliens was, maybe it *was* just a wayside picknick. No discernible strategy, several points on the globe ar hit by something resembling meteor strikes. That's it.
**unkown** One recentish "invasion" story - I forgot the author and name of the story - has aline nanotech somethings land in Kenya. The somethings build weird structures, change the landscape and are dangerous to touch. This leads to efforts to research them, plunder parts (similar to wayside picknick, except the zone is expanding). | My advice is split the planet into geographical regions(as in deciding the areas for certain ground forces to take and not political). and send specialised ground forces to take each region.When a ground force finishes conquest(either taking land by force or making the enemy surrender) they check every location resistance fighters could hide in then they leave half their forces to occupy the land while the other half assists ground units that are losing once the planet is taken they clear potential threats to their power(this strategy only works after sending scouts to map out different ecosystems and learning of the political landscape)Edit:the strategy was designed to be superior to just land troops in one area and have them spread out from there |
153,566 | The sea is used as an analogy in space travel, and sometimes it works well. Ships sail on long journeys, between distant lands, across a hostile medium.
But these analogies tend to break down when it comes to planetary invasion. Planets aren't like islands: because an island has a coast that can be defended, and defenders can retreat into the interior of the island. This happened a lot in WW2, particularly in the Pacific. But in terms of planetary invasion... the entire planet surface is the coast, and the interior of the planet (the mantle) is not something which can really be retreated into.
Much more important, bridgeheads do not seem to be important. Spaceships can land virtually anywhere there is a flat surface on a planet. The concept of a front line in terms of planetary invasion seems somewhat irrelevant if you can land an army behind what is the "front" line.
Clearly there must be means to counter spaceships. Spaceships when in close orbit, or in the atmosphere, become subject to the same rules as aircraft. They can be hit by terrestrial missiles and other vessels. But all this means is that air superiority be achieved before invasion, and defences hit from long distance by bombardment.
Which brings me to the last point: why invade at all to destroy an enemy? Most structures of a civilisation are probably going to be on a surface. It is, after all, more difficult to build underground than on a surface. That means that most items of value can be simply blasted from above. Sure, some command points, armament storage and production facilities, and offices of government may be transferred to secure underground bunkers, but this still means essentially conceding the surface to whatever punishment the attacker chooses. There can be no counterstrike, merely a populace putting its heads between its legs and hoping for the best. Perhaps in the event of a siege there could be hope of external assistance, but this still makes it such that the attacked planet is itself left defenseless.
So is there any way for realistic planetary invasion have any meaningful strategy? I have never seen such in fiction - the invasion just "happens" and we generally catch up with the consequences of the invasion. If the invasion is defeated, it is always some Deus Ex Machina that has nothing to do with strategy relating to the invasion itself.
Edit: By "invade a planet" I mean from a strategic, military point of view. The Allied invasion of France during WW2, for instance, wasn't just an exercise to liberate western Europe - the Axis forces needed to be eliminated on the ground (aircraft not used in combined arms offensives were of limited use except in urban bombing, and urban bombing had no significant effect until airbases within mainland Europe were available). The option to float thousands of gunships a mile up to rain down precise fire 24 hours a day simply wasn't available, even when looking at recent historical wars. Had it been available in something like WW2, there simply would have been no Axis forces left to resist invasion.
Edit 2: I should probably have defined the parameters of this question as **EITHER** "Why would an interstellar civilisation invade instead of attacking a planet" **OR** "Given that an interstellar civilisation is invading a planet, how would meaningful defence be mounted?". I was kind of leaning in favour of the latter definition of the question, but that's a damn difficult question to answer (if it wasn't we would have seen it in sci-fi settings already). | 2019/08/22 | [
"https://worldbuilding.stackexchange.com/questions/153566",
"https://worldbuilding.stackexchange.com",
"https://worldbuilding.stackexchange.com/users/15774/"
] | Here is my take on this.
Moving up/ down from a gravity well is expensive, slow, and prone to catastrophic failure.
Luckily we have space elevators (more realistically space rings) that allow us to use the power of the sun to lift things too/from the surface of the planet, instead of wasteing the unobtanium that powers our handwavium drive.
Space elevators are extremely expensive to build, it's a megastructrue. Not something you would destroy out of hand. As not having a space elevator makes the planet worthless for both the invader and the defender. Therefore neither side wants to destroy the space elevator.
Invasions would start out with odsts falling from the sky to secure the base of a space elevator. While marines capture the official super structure.
The landing point than becomes your primary beach head as it is drastically cheaper to get supplies planetside thru the elevator than a hot drop.
But why don't you just glass the planet? Or use bio weapons to clear out the unwanted population?
The solution is that this was done in the past, leaving behind tomb worlds and the shattered husks of planets. The civilized species got together in a galactic convention and decided to lay out the rules of war they expect everyone to follow
Breaking this convention, will lead to all other civilized species declaring war on you. Not something you want. | ### The defense: An array of really big satellite turrets.
Our current technology has no effective means of fighting off an attack from space, but unless we are talking about an invasion from a vastly technologically superior species we can presume that as spacecraft technology advanced, so did the defenses needed to defend against those spacecraft.
The first use of aircraft in warfare had no effective defenses, but anti-aircraft artillery quickly evolved to shoot down incoming planes. What we need, then, is anti-spacecraft guns - preferably positioned in orbit.
The key technology necessary for defending against an interplanetary invasion is a really long-ranged gun capable of hitting anything within a large, spherical region - anywhere it is not blocked by the planet itself. This will allow you to set up a defensive array with a relatively small number of satellites. The key to invading a planet, therefore, will be to either destroy one or more of these satellites or sneak past them.
### The invasion: a Trojan Horse.
Since there is No Stealth In Space, if you intend to sneak past these satellites the only way to do so will be to pose as something you're not - sneak a bunch of soldiers inside what appears to be a group of benign cargo ships, for instance. This will, naturally, limit the number of troops you can field and the places you can field them.
The objective of the invasion will not be to conquer the planet's surface with infantry, but to take control of the base or bases that control the Planetary Defense Array. Once the satellites are down, the planet will be vulnerable to space invasion, rendering it effectively defenseless.
If you have warp gate technology, the initial invaders could set up a portal on the ground, allowing you to field more troops but restricting their entry point, forcing you to use more conventional ground-based strategy. |
138,227 | Which one is correct? Or are both acceptable?
\*He earned an MD and a gold medal from St James for his dissertation.
\*He earned an MD and gold medal from St James for his dissertation.
\*He was appointed Surgeon at Hospital A and Hospital B.
\*He was appointed Surgeon at Hospital A and at Hospital B. | 2013/11/19 | [
"https://english.stackexchange.com/questions/138227",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/57611/"
] | In the second example, the second *at* could imply a separation of the two functions.
If the consultant surgeon post was a single employment that covered both hospitals, it would be omitted, whereas it would be included if there were two separate appointments. | In the first example I would go for "He earned an MD and a gold medal from St Andrews", because to leave out the second "a" implies that the gold medal is an enhancement to the MD in the sense of "DSO and bar".
In the second example, however, "He was appointed Consultant Surgeon at Hospital A and Hospital B" is fine, because the first "at" functions in linking both hospitals with "he was appointed Consultant Surgeon".
However, you'd keep both "at"s in if you were going to extend the sentence to say something different about what he was appointed to in Hospital B - "He was appointed Consultant Surgeon at Hospital A, and at Hospital B he was recognised for long service". |
3,582 | Last year, I bought a 2005 Volvo S60 for my wife to drive to her job.
The car had 103,000 miles on the clock, so a few weeks ago, I installed a new timing belt, tensioner, idle pulley, and water pump. In order to complete the installation, it was necessary to pull the power steering fluid reservoir off to the side to gain the clearance to remove the timing belt. The timing belt installation was completed without any serious incidents.
I was also advised by a mechanic that the car needs to have new lower control arms on the front, as well as new joints. He said that the joints are "slinging grease". I don't even know exactly what he meant by that.
I inspected the hoses on the power steering fluid reservoir as best I could, but I can't see that it's leaking; I really have not idea how the car is losing its power steering fluid.
I have refilled the car's power steering fluid twice in the last week. What is the best course of action to take to find the problem and get it fixed? | 2012/05/25 | [
"https://mechanics.stackexchange.com/questions/3582",
"https://mechanics.stackexchange.com",
"https://mechanics.stackexchange.com/users/1095/"
] | As for the blower only working on max, that screams [resistor pack](http://www.rockauto.com/catalog/raframecatalog.php?carcode=1424405&parttype=6557&partkey=2194770&a=FRc1424405k2194770-2899550). It's usually in the passenger foot well near the blower motor itself. [Sounds like](http://www.chryslerforum.com/forum/chrysler-sebring-14/blower-motor-resistor-diy-2004-sebring-sedan-8772/) it's held in by two 8mm bolts in your case. Shouldn't be too terrible of a job, but you might want to avoid it if you've got back or neck problems. I usually put the seat back down as far as it will go and lay down facing forward and pull myself up under the dash. If you've been running the blower exclusively on high for a while, it might be the next thing to go out. Last time I changed a resistor, the blower worked for a couple days then died. That was a little more involved, but still doable if you don't mind being upside down in a tight space.
As for the temperature falling off, the two things that come to mind for me are maybe a clogged heater core and / or thermostat. What are your engine temps like? | The heat problem sounds like poor coolant circulation, possibly due to low fluid level or partial clogging. |
25,796,280 | When iPhone 5 first came out we had to go through the silliness of adding a Default-568h@2x.png to the project to get the app to use the full height of the iPhone 5. In late 2014 are we still doing that?
We have asset catalogs and the LaunchScreen.xib file. Do we still need to add the Default-568h@2x.png file? If so, where does it go now? I've tried a few different things and I can't get rid of the black bars in a new app created with Xcode 6 GM. | 2014/09/11 | [
"https://Stackoverflow.com/questions/25796280",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/1151334/"
] | As stated by rmaddy in the comments, if you are supporting iOS < 8, you still need to do this:
General / App Icons and Launch Images
Launch Image Source - select LaunchImage for asset catalog.
Add a 640x1136 image for the "Retina 4" option.
So I guess the LaunchScreen.xib is useless if you target iOS < 8, unless you want to update both that and the asset catalog when the image changes. | if you are not creating new Project,
like changing or rename old Project,
you should remove all Images.xcassets from Project.
then
Navigate to project settings
Under "App Icons and Launch Images" click on "Use Asset Catalog"
Select "Migrate" on the popup that appears. make new Asset.
it work pretty fine for me.
env is
xocde6.1 iPhoneSimulator5/5S/6/6+ on iOS8 |
245,252 | Basically I have a few files / folders that I want permanently deleted. I deleted them securely with hardwipe, but when I try to search into the folder where they were located with Wondershare Recoverit, the foldernames, filenames, even some parts the docs/txt's/images are still visible even partly recoverable.
I've tried several solutions, cleaning USN/MFT with programs like Recuvera/Privazer/CCleaner/Revo Uninstaller. I also tried filling up my entire SSD with data, only 100MB of free space left.
Does anyone have any additional programs or an idea how I can prevent specialized programs from finding these folders/files? | 2021/02/23 | [
"https://security.stackexchange.com/questions/245252",
"https://security.stackexchange.com",
"https://security.stackexchange.com/users/251650/"
] | If you need the files deleted with any degree of confidence, while still being constrained to continue using the drive, you will have to abandon the possibility of preserving the OS installation that's on the drive now.
From there, you can simply use any disk-wiping tool (for an SSD, **even a single pass** of Random data in something like [DBAN](https://sourceforge.net/projects/dban/) would be sufficient), as long as you do write something ([other than zeroes](https://serverfault.com/a/282583/175102)) to every sector of the drive *without* deleting anything at all between writing the first and last sectors.
You [may or may not](https://security.stackexchange.com/q/41676/26186) be interested in trying the drive's native Secure Erase capability; if supported, it will provide drastically reduced risk of an attacker recovering the data, as well as causing drastically less wear on the drive (a big plus if you can't just destroy it because you intend to continue using it).
---
In the future, you should encrypt data at rest that you're likely to need securely deleted. It's much easier to simply dispose of a few encryption keys (especially when stored in an HSM, such as a [smartcard](/questions/tagged/smartcard "show questions tagged 'smartcard'") or [tpm](/questions/tagged/tpm "show questions tagged 'tpm'"), both of which generally support reliable deletion of the keys as a routine operation) than to do all the song and dance required to sanitize a drive, especially an SSD. | Software deletion is not effective. I assume that your hard-drive is a magnetic drive. The best way to delete your files is degaussing.
Next, you can use inbuild deletion commands. Sometimes even those commands also not working properly.
In addition to that, you can use a purging method. It also has some level of data remanence.
In SSD you can encrypt and delete. Then even it is restored, it will not be able to open.
If you have highly secret data, destruction of the media is recommended. |
3,703 | 1) Can a state be entangled without also being a superposition? (Please give an example.)
2) Can a state be a superposition without being entangled? (Again, an example please.)
3) And what about a cat state?
I am royally confused, and a little bit of googling didn't help.
This question is partly motivated by the recent news announcement (Nature, NYTimes) that ten billion entangled pairs have been created.
4) Are these spin pairs also in a superposition?
5) Does this count as a cat state? | 2011/01/23 | [
"https://physics.stackexchange.com/questions/3703",
"https://physics.stackexchange.com",
"https://physics.stackexchange.com/users/1172/"
] | Any discussion of entanglement implies you are thinking of (at least) two separate systems. Superpositions on the other hand, can also apply to situations where you are only looking at a single system. Keeping this in mind:
>
> "Can a state be entangled without also
> being a superposition? (Please give an
> example)"
>
>
>
No. An entangled state is by definition a state which cannot be written as a separable product in any basis. Whatever basis you choose, the state will be a superposition of products of the separate systems.
>
> "Can a state be a superposition
> without being entangled? (Again, an
> example please)"
>
>
>
Of course. A trivial example would be a single isolated system for which you can usually find some basis in which the state is in a superposition. And single isolated systems cannot be entangled with anything else because.. well.. they are single isolated systems - and like I said before, entanglement applies to a situation where you have divided your world into separate systems that can interact with each other.
>
> "And what about a cat state?"
>
>
>
A Schrodinger Cat state is usually used to refer to a *macroscopic* system which is in a superposition of two or more states (in the eigenstate basis of some physical observable like energy or position). Real cats in geiger-counter-poison-rigged boxes probably won't be in such superpositions due to [decoherence](http://en.wikipedia.org/wiki/Quantum_decoherence) but there are some surprisingly large objects like buckyballs and macromolecules which have been shown to exist in superpositions.
>
> "Are these spin pairs also in a
> superposition?"
>
>
>
Yes, in all bases, because they are entangled. Allegedly :)
>
> "Does this count as a cat state?"
>
>
>
I'm not sure because I haven't read the whole paper and also because the definition of a cat state depends on what you consider macroscopic. | Superposition involves linking multiple particles via a single dimensional thread of wave energy. In contrast, entanglement involves the separation of space-time; i.e. a single point in space split into more than one location. |
481,585 | >
> **This guy's alright in my book**, because he used the word "rapscallion".
>
>
> [Source](https://meta.stackoverflow.com/questions/378976/unexplained-clutter-in-a-post-edited-back-in-by-author/379059?noredirect=1#comment663338_379059)
>
>
>
What it means by alright in my book? | 2019/01/17 | [
"https://english.stackexchange.com/questions/481585",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/252898/"
] | "In my book" means "in my opinion", "according to my belief system". The commenter approves of the other person's vocabulary. | That means he likes the way that guy wrote because that same guy used a word he particularly enjoyed. |
61,249 | I have 20+ WP sites installed for clients on different web hotels. All WP-installs are updated to run latest versions of everything.
On some of my sites, the update- and install screens work as expected when I update or install a theme/plugin, the page updates and ends displaying the sucess/finished message.
On some of my sites however, these screens always just show the first line like "downloading package" (or something like that, you get the point), but then they never progress. It seems however that everything always gets installed updated as it should. Even when I do a batch update of more plugins.
It seems to be a hosting issue, as it's the same for all sites on the same host.
Does anyone have a hint at what it might be in the server configuration that is preventing these screens from updating on the progress? | 2012/08/08 | [
"https://wordpress.stackexchange.com/questions/61249",
"https://wordpress.stackexchange.com",
"https://wordpress.stackexchange.com/users/2071/"
] | Make sure the folders permission (CHMOD) are right. See - [Wordpress Specific permissions modes](http://codex.wordpress.org/Changing_File_Permissions)
It could also maybe be a timeout problem on the server? | I think I found a way to get it work. If it is your own server you can try to change the php-mode from Fast-CGI to ModPHP/SuPHP - Those both modes work for me in this case. I wasn't able to activate it for FastCGI tho.
If someone does know an answer to this, please let me know. |
18,158,712 | I have universal single view app. In the iphone I created a table view and works just fine but I add a tableview in the iPad nib but the table view never display in my ipad. Any of you can tell me what I'm doing wrong or how can fix this
I really appreciate your help
P.S. Both nibs had been configure to files owner in the same way | 2013/08/10 | [
"https://Stackoverflow.com/questions/18158712",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/2669815/"
] | There isn't a single framework that I know of but you can use JSLint for Javascript or other frameworks as Raoul has mentioned. For css and html use the wc3 validators.
<http://validator.w3.org/> for html and <http://jigsaw.w3.org/css-validator/> for css | [Jasmine](http://pivotal.github.io/jasmine/)
is my preferred testing framework for Javascript. |
18,158,712 | I have universal single view app. In the iphone I created a table view and works just fine but I add a tableview in the iPad nib but the table view never display in my ipad. Any of you can tell me what I'm doing wrong or how can fix this
I really appreciate your help
P.S. Both nibs had been configure to files owner in the same way | 2013/08/10 | [
"https://Stackoverflow.com/questions/18158712",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/2669815/"
] | 1. Javascript - <http://www.jslint.com/>, <http://sinonjs.org>,
<http://qunitjs.com/> to name a few
2. CSS Use <http://jigsaw.w3.org/css-validator/>
3. HTML - <http://validator.w3.org/> | [Jasmine](http://pivotal.github.io/jasmine/)
is my preferred testing framework for Javascript. |
6,075 | There are a few posts that I've come across that seem to imply that using regular encryption and a MAC might be better than using the newer AEAD (ie: AES/GCM) modes.
<https://www.daemonology.net/blog/2009-06-24-encrypt-then-mac.html>
<https://blog.cryptographyengineering.com/2011/12/matt-green-smackdown-watch-are-aead.html>
My questions are thus:
Is an AEAD more likely to fail (being subject to chosen plaintext attacks, versus HMAC protecting the encrypted part more securely), and if so, does it fail in a more catastrophic way?
Assuming that you have securely generated both the HMAC and encryption keys, is Encrypt+HMAC therefore more secure? | 2013/01/22 | [
"https://crypto.stackexchange.com/questions/6075",
"https://crypto.stackexchange.com",
"https://crypto.stackexchange.com/users/4814/"
] | This is something I tend to disagree somewhat with Colin Percival on.
You should use Encrypt-then-HMAC *if* and *only if* you can get it right. The biggest pitfall is using a short-circuiting string comparison versus a constant-time string comparison. Given the former, people can use timing attacks to forge valid HMACs for arbitrary ciphertexts. With an encryption mode like CBC, this could be used to read the contents of encrypted messages. Other pitfalls include accidentally implementing Encrypt-and-MAC or MAC-then-encrypt, which have historically had vulnerabilities related to their construction.
On the other hand, EAX and GCM modes provide this feature transparently. There are some concerns about potential side-channel attacks against dedicated AEAD modes, and there is also the conceptual issue of potentially passing unauthenticated packets to your decryption algorithm. You, of course, have to get details like unique IVs correct, but you also have this requirement for Encrypt-then-MAC.
That said, potential flaws in EAX and GCM implementations can be fixed for many people at once with patches to the relevant libraries. Flaws where non-cryptographers naïvely compare HMACs are epidemic, and even high-profile projects like Google's KeyCzar have made this simple mistake. If you *absolutely know what you're doing*, Encrypt-then-HMAC is a provably secure construct. If you *don't know what you're doing*, something like EAX or GCM may be found to have weaknesses, but they are assuredly better than implementing something yourself.
Edit: I may have made Encrypt-then-HMAC sound easier than it actually is. One other major pitfall of Encrypt-then-HMAC is not HMACing enough information, or not HMACing the information correctly. The HMAC *must* include the ciphertext, the additional authentication data, and the initialization vector. It *probably must* also (perhaps someone else can confirm or deny this) include a descriptor to identify the encryption algorithm used. To pass these fields into the HMAC, you *must* use a format that unambiguously delineates fields. The easiest way to do this is to prepend a 4-byte big-endian length before any variable-length field (usually just authentication data and ciphertext), but doing this for all fields is probably a good idea. If you don't HMAC all this information, an attacker can modify any of the data not included. If you don't HMAC them unambiguously, an attacker can manipulate message boundaries, which could allow him to conduct an exploit.
Edit 2: Another detail of Encrypt-then-HMAC I've forgotten. Hopefully you can see how hard this is to get right. Ideally, you should never reuse the same key across security contexts. I'm unaware of any attacks that would result from using your encryption key as the key for the HMAC, but best practice is to use a different key for encryption and authentication. One simple approach (assuming a 256-bit encryption algorithm and 256-bit HMAC) is to use a "virtual" 512-bit key. Use the first half for encryption and the last half for authentication. Another approach is to use a 256-bit key, but pass it through HKDF with a 512-bit output; use this as before: split it into two parts, use one for encryption and one for authentication.
Edit 3: I asked a [highly relevant question](https://security.stackexchange.com/questions/20464/when-authenticating-ciphertexts-what-should-be-hmaced) on the security StackExchange a few months ago. Thomas Pornin's detailed answer may be helpful. | I think this question splits into two parts, the one is about AEAD in principle vs. Encrypt+HMAC, the other about AES-GCM.
As far as I know, Galois counter mode may have some weaknesses in the checksum, which might reduce its strength, and a well-known limitation to transfer size (64GB) before you definitely should renegotiate; read this paper for more information: <http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/comments/CWC-GCM/Ferguson2.pdf>
I also recall reading a paper comparing the galois field MAC computation with poly1305 from DJB, pointing out that the prime modulus (2^130-5) has significantly better properties. That's not bad enough for practical attacks, though.
These weaknesses are related to the particular AEAD encryption scheme AES-GCM; others are more secure. Examples of AEAD cipher suites which are considered more secure than AES-GCM are ChaCha20+Poly1305 from DJB, and Keccak in duplex mode.
The general picture however is really that AEAD is much, much easier to get right as mere user of a cryptographic library than Encrypt+HMAC. That does not mean that they have to be technically different from Encrypt+HMAC, just that you use a library where both the encryption and the HMAC is combined, like e.g. ChaCha20+Poly1305. Technically, ChaCha20 is just a stream cipher without authentication, and Poly1305 is just authentication. On the other hand, Keccak in duplex mode is really computing both authentication and encryption with the same operation, so it's integrated by design. |
6,075 | There are a few posts that I've come across that seem to imply that using regular encryption and a MAC might be better than using the newer AEAD (ie: AES/GCM) modes.
<https://www.daemonology.net/blog/2009-06-24-encrypt-then-mac.html>
<https://blog.cryptographyengineering.com/2011/12/matt-green-smackdown-watch-are-aead.html>
My questions are thus:
Is an AEAD more likely to fail (being subject to chosen plaintext attacks, versus HMAC protecting the encrypted part more securely), and if so, does it fail in a more catastrophic way?
Assuming that you have securely generated both the HMAC and encryption keys, is Encrypt+HMAC therefore more secure? | 2013/01/22 | [
"https://crypto.stackexchange.com/questions/6075",
"https://crypto.stackexchange.com",
"https://crypto.stackexchange.com/users/4814/"
] | This is something I tend to disagree somewhat with Colin Percival on.
You should use Encrypt-then-HMAC *if* and *only if* you can get it right. The biggest pitfall is using a short-circuiting string comparison versus a constant-time string comparison. Given the former, people can use timing attacks to forge valid HMACs for arbitrary ciphertexts. With an encryption mode like CBC, this could be used to read the contents of encrypted messages. Other pitfalls include accidentally implementing Encrypt-and-MAC or MAC-then-encrypt, which have historically had vulnerabilities related to their construction.
On the other hand, EAX and GCM modes provide this feature transparently. There are some concerns about potential side-channel attacks against dedicated AEAD modes, and there is also the conceptual issue of potentially passing unauthenticated packets to your decryption algorithm. You, of course, have to get details like unique IVs correct, but you also have this requirement for Encrypt-then-MAC.
That said, potential flaws in EAX and GCM implementations can be fixed for many people at once with patches to the relevant libraries. Flaws where non-cryptographers naïvely compare HMACs are epidemic, and even high-profile projects like Google's KeyCzar have made this simple mistake. If you *absolutely know what you're doing*, Encrypt-then-HMAC is a provably secure construct. If you *don't know what you're doing*, something like EAX or GCM may be found to have weaknesses, but they are assuredly better than implementing something yourself.
Edit: I may have made Encrypt-then-HMAC sound easier than it actually is. One other major pitfall of Encrypt-then-HMAC is not HMACing enough information, or not HMACing the information correctly. The HMAC *must* include the ciphertext, the additional authentication data, and the initialization vector. It *probably must* also (perhaps someone else can confirm or deny this) include a descriptor to identify the encryption algorithm used. To pass these fields into the HMAC, you *must* use a format that unambiguously delineates fields. The easiest way to do this is to prepend a 4-byte big-endian length before any variable-length field (usually just authentication data and ciphertext), but doing this for all fields is probably a good idea. If you don't HMAC all this information, an attacker can modify any of the data not included. If you don't HMAC them unambiguously, an attacker can manipulate message boundaries, which could allow him to conduct an exploit.
Edit 2: Another detail of Encrypt-then-HMAC I've forgotten. Hopefully you can see how hard this is to get right. Ideally, you should never reuse the same key across security contexts. I'm unaware of any attacks that would result from using your encryption key as the key for the HMAC, but best practice is to use a different key for encryption and authentication. One simple approach (assuming a 256-bit encryption algorithm and 256-bit HMAC) is to use a "virtual" 512-bit key. Use the first half for encryption and the last half for authentication. Another approach is to use a 256-bit key, but pass it through HKDF with a 512-bit output; use this as before: split it into two parts, use one for encryption and one for authentication.
Edit 3: I asked a [highly relevant question](https://security.stackexchange.com/questions/20464/when-authenticating-ciphertexts-what-should-be-hmaced) on the security StackExchange a few months ago. Thomas Pornin's detailed answer may be helpful. | As an important update, more recent research has revealed that the main way Encrypt-then-MAC is stronger than standardised AEADs is that it's [committing](https://www.youtube.com/watch?v=h-T1bQTt4_Y) if:
1. You use a single key for both encryption and authentication (not recommended) or derive the encryption key and MAC key from the same input keying material using a secure KDF (recommended). [[Source](https://eprint.iacr.org/2020/1491.pdf)]
2. You use a 256-bit+ authentication tag because you want collision resistance. [[Source](https://eprint.iacr.org/2017/664.pdf)]
Simply put, being 'committing' means it should be infeasible for authentication to pass using multiple different keys and for the authentication tag to repeat for different messages and keys.
You would naively expect an AEAD to have this sort of property, but the popular standardised AEADs, such as (X)ChaCha20-Poly1305, AES-GCM, and AES-OCB, are not committing. This can allow for [attacks](https://eprint.iacr.org/2020/1491.pdf) in [some](https://crypto.stackexchange.com/questions/88716/understanding-the-impact-of-partitioning-oracle-attacks-on-stream-ciphers) scenarios, which [can](https://eprint.iacr.org/2020/1456.pdf) be exploitable in practice. It's a situation that feels reminiscent of length extension attacks, which were fixed in SHA3.
Encrypt-then-MAC is the current [recommended](https://mailarchive.ietf.org/arch/msg/cfrg/2W9LoeeiRzAiTWVnDsyxvjYPPmo/) solution by some of the commitment research authors. Thus, I would argue that committing Encrypt-then-MAC implementations with support for additional data (aka equivalent to AEADs) should be standardised and added to cryptographic libraries so they're as easy to use as regular AEAD modes. Then the only argument in favour of regular AEADs is that they're more efficient, but the gap depends on the MAC used (e.g. BLAKE3 can be faster than Poly1305). |
6,246 | I read that:
>
> Take a cupful of water in a beaker and add a few drops of dilute
> sulfuric acid. Heat the water. When it starts boiling add copper
> sulfate powder slowly while stirring continuously.
> Continue adding copper sulfate powder till no more powder can be
> dissolved. Filter the solution. Allow it to cool. Do not disturb the
> solution when it is cooling. Look at the solution after some time. Can
> you see the crystals of copper sulfate? If not, wait for some more
> time.
>
>
>
So why is sulfuric acid required in this experiment? | 2013/09/18 | [
"https://chemistry.stackexchange.com/questions/6246",
"https://chemistry.stackexchange.com",
"https://chemistry.stackexchange.com/users/2326/"
] | The reason behind this is the orientation of the overlapped orbitals. Sigma bonds result from head-on(co-axial) overlapping while pi bonds are outcome of lateral(para-axial) overlapping. Here is a pictorial representation of ethene(sp2 hybridized C atoms) :
***The greater the extent of overlapping, the higher the probability of finding the valence electrons in between the nuclei and hence the bond will be stronger & shorter.***
In MOT, this can be explained using [Overlap Integral](http://en.wikipedia.org/wiki/Orbital_overlap). This is how Atkins depicts it :
***In simple terms, after forming a sigma-bond (a pre-requisite for pi-bonds), the two atoms get locked along the inter-nuclear axis. As a result, the orbitals available for pi-bonding can only partially overlap, thus forming a weaker bond.*** | Unsaturated compounds (due to the existence of a double bond) are more reactive than saturated compounds, because the electron density at the internuclear axis is zero in a pi bond (in contrast to the sigma bond). |
6,246 | I read that:
>
> Take a cupful of water in a beaker and add a few drops of dilute
> sulfuric acid. Heat the water. When it starts boiling add copper
> sulfate powder slowly while stirring continuously.
> Continue adding copper sulfate powder till no more powder can be
> dissolved. Filter the solution. Allow it to cool. Do not disturb the
> solution when it is cooling. Look at the solution after some time. Can
> you see the crystals of copper sulfate? If not, wait for some more
> time.
>
>
>
So why is sulfuric acid required in this experiment? | 2013/09/18 | [
"https://chemistry.stackexchange.com/questions/6246",
"https://chemistry.stackexchange.com",
"https://chemistry.stackexchange.com/users/2326/"
] | The reason behind this is the orientation of the overlapped orbitals. Sigma bonds result from head-on(co-axial) overlapping while pi bonds are outcome of lateral(para-axial) overlapping. Here is a pictorial representation of ethene(sp2 hybridized C atoms) :
***The greater the extent of overlapping, the higher the probability of finding the valence electrons in between the nuclei and hence the bond will be stronger & shorter.***
In MOT, this can be explained using [Overlap Integral](http://en.wikipedia.org/wiki/Orbital_overlap). This is how Atkins depicts it :
***In simple terms, after forming a sigma-bond (a pre-requisite for pi-bonds), the two atoms get locked along the inter-nuclear axis. As a result, the orbitals available for pi-bonding can only partially overlap, thus forming a weaker bond.*** | Pi bonds involve sideways overlap while sigma bond involves head on or axial overlap. Axial overlaps have higher degree of overlapping than sideways overlap. |
6,246 | I read that:
>
> Take a cupful of water in a beaker and add a few drops of dilute
> sulfuric acid. Heat the water. When it starts boiling add copper
> sulfate powder slowly while stirring continuously.
> Continue adding copper sulfate powder till no more powder can be
> dissolved. Filter the solution. Allow it to cool. Do not disturb the
> solution when it is cooling. Look at the solution after some time. Can
> you see the crystals of copper sulfate? If not, wait for some more
> time.
>
>
>
So why is sulfuric acid required in this experiment? | 2013/09/18 | [
"https://chemistry.stackexchange.com/questions/6246",
"https://chemistry.stackexchange.com",
"https://chemistry.stackexchange.com/users/2326/"
] | The reason behind this is the orientation of the overlapped orbitals. Sigma bonds result from head-on(co-axial) overlapping while pi bonds are outcome of lateral(para-axial) overlapping. Here is a pictorial representation of ethene(sp2 hybridized C atoms) :
***The greater the extent of overlapping, the higher the probability of finding the valence electrons in between the nuclei and hence the bond will be stronger & shorter.***
In MOT, this can be explained using [Overlap Integral](http://en.wikipedia.org/wiki/Orbital_overlap). This is how Atkins depicts it :
***In simple terms, after forming a sigma-bond (a pre-requisite for pi-bonds), the two atoms get locked along the inter-nuclear axis. As a result, the orbitals available for pi-bonding can only partially overlap, thus forming a weaker bond.*** | As stated previously, it is due to the head-on overlap of sigma bonds and the lateral overlap of pi-bonds.
The smaller overlap of pi bonds also explains why double and triple bonds basically exist only for 2nd row elements (C,N,O especially) and not for higher row elements. A C=C bond has a length of 133 pm. A Si-Si bond length is at around 186 pm, therefore the contribution of the pi-integral overlap is almost negligible.
The inability of Silicium to form strong pi bonds is also one of the answer why life on earth is carbon based and not silicium based, since the richness of organic chemistry is in part due to the ability of carbon to form strong double and triple bonds. |
6,246 | I read that:
>
> Take a cupful of water in a beaker and add a few drops of dilute
> sulfuric acid. Heat the water. When it starts boiling add copper
> sulfate powder slowly while stirring continuously.
> Continue adding copper sulfate powder till no more powder can be
> dissolved. Filter the solution. Allow it to cool. Do not disturb the
> solution when it is cooling. Look at the solution after some time. Can
> you see the crystals of copper sulfate? If not, wait for some more
> time.
>
>
>
So why is sulfuric acid required in this experiment? | 2013/09/18 | [
"https://chemistry.stackexchange.com/questions/6246",
"https://chemistry.stackexchange.com",
"https://chemistry.stackexchange.com/users/2326/"
] | Pi bonds involve sideways overlap while sigma bond involves head on or axial overlap. Axial overlaps have higher degree of overlapping than sideways overlap. | Unsaturated compounds (due to the existence of a double bond) are more reactive than saturated compounds, because the electron density at the internuclear axis is zero in a pi bond (in contrast to the sigma bond). |
6,246 | I read that:
>
> Take a cupful of water in a beaker and add a few drops of dilute
> sulfuric acid. Heat the water. When it starts boiling add copper
> sulfate powder slowly while stirring continuously.
> Continue adding copper sulfate powder till no more powder can be
> dissolved. Filter the solution. Allow it to cool. Do not disturb the
> solution when it is cooling. Look at the solution after some time. Can
> you see the crystals of copper sulfate? If not, wait for some more
> time.
>
>
>
So why is sulfuric acid required in this experiment? | 2013/09/18 | [
"https://chemistry.stackexchange.com/questions/6246",
"https://chemistry.stackexchange.com",
"https://chemistry.stackexchange.com/users/2326/"
] | As stated previously, it is due to the head-on overlap of sigma bonds and the lateral overlap of pi-bonds.
The smaller overlap of pi bonds also explains why double and triple bonds basically exist only for 2nd row elements (C,N,O especially) and not for higher row elements. A C=C bond has a length of 133 pm. A Si-Si bond length is at around 186 pm, therefore the contribution of the pi-integral overlap is almost negligible.
The inability of Silicium to form strong pi bonds is also one of the answer why life on earth is carbon based and not silicium based, since the richness of organic chemistry is in part due to the ability of carbon to form strong double and triple bonds. | Unsaturated compounds (due to the existence of a double bond) are more reactive than saturated compounds, because the electron density at the internuclear axis is zero in a pi bond (in contrast to the sigma bond). |
6,246 | I read that:
>
> Take a cupful of water in a beaker and add a few drops of dilute
> sulfuric acid. Heat the water. When it starts boiling add copper
> sulfate powder slowly while stirring continuously.
> Continue adding copper sulfate powder till no more powder can be
> dissolved. Filter the solution. Allow it to cool. Do not disturb the
> solution when it is cooling. Look at the solution after some time. Can
> you see the crystals of copper sulfate? If not, wait for some more
> time.
>
>
>
So why is sulfuric acid required in this experiment? | 2013/09/18 | [
"https://chemistry.stackexchange.com/questions/6246",
"https://chemistry.stackexchange.com",
"https://chemistry.stackexchange.com/users/2326/"
] | As stated previously, it is due to the head-on overlap of sigma bonds and the lateral overlap of pi-bonds.
The smaller overlap of pi bonds also explains why double and triple bonds basically exist only for 2nd row elements (C,N,O especially) and not for higher row elements. A C=C bond has a length of 133 pm. A Si-Si bond length is at around 186 pm, therefore the contribution of the pi-integral overlap is almost negligible.
The inability of Silicium to form strong pi bonds is also one of the answer why life on earth is carbon based and not silicium based, since the richness of organic chemistry is in part due to the ability of carbon to form strong double and triple bonds. | Pi bonds involve sideways overlap while sigma bond involves head on or axial overlap. Axial overlaps have higher degree of overlapping than sideways overlap. |
20,001 | I hike in an area where packing in all your water is the only option. For longer hikes when it's warmer one bladder won't hold enough. Does anyone make a practical way to connect two together so you have only one feed hose that will draw from two bladders? | 2018/07/27 | [
"https://outdoors.stackexchange.com/questions/20001",
"https://outdoors.stackexchange.com",
"https://outdoors.stackexchange.com/users/381/"
] | No, pretty sure there isn't one but you do have a couple of options,
* Just bring two bladders and switch to the other when empty.
* There are 6 liter MSR dromedaries that I have used for when you need to pack water in larger amounts.
* There are double hydration bladders with two chambers, but it seems like the idea is to keep water and electrolytes separate, not to double the capacity.
Also, I always bring a Nalgene bottle along as well, in case the bladders get holes in them (this is also best practice from what I have read about hiking in the Grand Canyon). | The best thing to do would be to simply bring two water bladders and switch the hoses over your shoulder after the first is emptied. Alternately, you could try routing two hoses over your one shoulder. Many bags also provide the option of routing the hose over your left *or* right shoulder, if your bag is like this then you could try routing one hose for each bladder over both shoulders. Trying to rig two bladders together sounds like a wet mess waiting to happen to in my opinion. |
20,001 | I hike in an area where packing in all your water is the only option. For longer hikes when it's warmer one bladder won't hold enough. Does anyone make a practical way to connect two together so you have only one feed hose that will draw from two bladders? | 2018/07/27 | [
"https://outdoors.stackexchange.com/questions/20001",
"https://outdoors.stackexchange.com",
"https://outdoors.stackexchange.com/users/381/"
] | I can imagine that there's nothing of the shelf available but this is nothing a little DIY can't fix.
Go to your local hardware or pet supply store and find a small aquarium hose T or Y fitting that matches the inner diameter of your bladder hose.
Simply cut the hoses of your bladders and attach the two bladders to the T fitting, then attach one of the hoses with a drinking end to the T fitting.
The hoses should be fine with just a friction fit but you can add two small zipties per connection for extra safety.
PS: This solution requires a willingness to void your warranty | No, pretty sure there isn't one but you do have a couple of options,
* Just bring two bladders and switch to the other when empty.
* There are 6 liter MSR dromedaries that I have used for when you need to pack water in larger amounts.
* There are double hydration bladders with two chambers, but it seems like the idea is to keep water and electrolytes separate, not to double the capacity.
Also, I always bring a Nalgene bottle along as well, in case the bladders get holes in them (this is also best practice from what I have read about hiking in the Grand Canyon). |
20,001 | I hike in an area where packing in all your water is the only option. For longer hikes when it's warmer one bladder won't hold enough. Does anyone make a practical way to connect two together so you have only one feed hose that will draw from two bladders? | 2018/07/27 | [
"https://outdoors.stackexchange.com/questions/20001",
"https://outdoors.stackexchange.com",
"https://outdoors.stackexchange.com/users/381/"
] | I can imagine that there's nothing of the shelf available but this is nothing a little DIY can't fix.
Go to your local hardware or pet supply store and find a small aquarium hose T or Y fitting that matches the inner diameter of your bladder hose.
Simply cut the hoses of your bladders and attach the two bladders to the T fitting, then attach one of the hoses with a drinking end to the T fitting.
The hoses should be fine with just a friction fit but you can add two small zipties per connection for extra safety.
PS: This solution requires a willingness to void your warranty | The best thing to do would be to simply bring two water bladders and switch the hoses over your shoulder after the first is emptied. Alternately, you could try routing two hoses over your one shoulder. Many bags also provide the option of routing the hose over your left *or* right shoulder, if your bag is like this then you could try routing one hose for each bladder over both shoulders. Trying to rig two bladders together sounds like a wet mess waiting to happen to in my opinion. |
430,882 | What is the best way to search strings for something like forum? i seen horrible string search and typically get worse the more strings you use rather then better.
I also may implement a title search so if the way to search title that is better then a body of string i'd love to hear that too | 2009/01/10 | [
"https://Stackoverflow.com/questions/430882",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/-1/"
] | Take a look at using [Lucene](http://lucene.apache.org/java/docs/) (Java) (or [Lucene.Net](http://incubator.apache.org/lucene.net/)) for full text search. Lucene is a text-mining API that allows you to index and search documents by title, text, author, etc. I've used a Ruby port of Lucene (Ferret or [acts\_as\_ferret](http://rm.jkraemer.net/projects/show/aaf)) to index a specialized mailing list and found that it works very well. | Not sure what you mean exactly by "Forum", but [Regular Expressions](http://www.regular-expressions.info/tutorial.html) may be a good place to start.
Too general? |
430,882 | What is the best way to search strings for something like forum? i seen horrible string search and typically get worse the more strings you use rather then better.
I also may implement a title search so if the way to search title that is better then a body of string i'd love to hear that too | 2009/01/10 | [
"https://Stackoverflow.com/questions/430882",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/-1/"
] | Take a look at using [Lucene](http://lucene.apache.org/java/docs/) (Java) (or [Lucene.Net](http://incubator.apache.org/lucene.net/)) for full text search. Lucene is a text-mining API that allows you to index and search documents by title, text, author, etc. I've used a Ruby port of Lucene (Ferret or [acts\_as\_ferret](http://rm.jkraemer.net/projects/show/aaf)) to index a specialized mailing list and found that it works very well. | I would in most cases suggest using the "Boyer Moore" string search algorithm.
You can read about it on wikipedia:
<http://en.wikipedia.org/wiki/Boyer%E2%80%93Moore_string_search_algorithm>
There's also a lot of example code around to look at, if you're not interested in trying to implement it yourself.
If performance isn't important at all, I would agree with using regular expressions. |
430,882 | What is the best way to search strings for something like forum? i seen horrible string search and typically get worse the more strings you use rather then better.
I also may implement a title search so if the way to search title that is better then a body of string i'd love to hear that too | 2009/01/10 | [
"https://Stackoverflow.com/questions/430882",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/-1/"
] | I would in most cases suggest using the "Boyer Moore" string search algorithm.
You can read about it on wikipedia:
<http://en.wikipedia.org/wiki/Boyer%E2%80%93Moore_string_search_algorithm>
There's also a lot of example code around to look at, if you're not interested in trying to implement it yourself.
If performance isn't important at all, I would agree with using regular expressions. | Not sure what you mean exactly by "Forum", but [Regular Expressions](http://www.regular-expressions.info/tutorial.html) may be a good place to start.
Too general? |
395,216 | I'm pretty new to the world of neural networks, so I'm asking this question, I'll explain in the process all the words used in the title so, if there's something unclear or wrong, I'll edit the question to solve.
I was watching this video <https://youtu.be/WSW-5m8lRMs?t=220> and the author stated that he is using an algorithm called Neat, I looked up on Wikipedia and found out what it's based on, but I couldn't find out how to code it, I'm assuming it's because it's not easy at all.
I've also looked online for how to create one and only found a tutorial on how to use it in python since it's a library, and that cut off all my hopes to code something like that all by myself.
The AI I want to code is for a game on mobile, so I need to use [Dart](https://www.dartlang.org/), and is to guide NPCs on a map to avoid enemies and survive by let's say seeking food.
As far as I was able to understand, the neat algorithm takes:
1. what the player can see
2. the action it can perform
3. a performance indicator.
And then it'll learn to make decisions based on the variables, for example, direct to a food source when the player is hungry or it'll die. So, the ai will be able to see all the food source locations, the other ais locations, and other things.
For the actions it can perform, he will be able to move in a direction defined as vectors of a maximum length, so for example (3, 7) defined in meters. The performance indicator will be how long the AI was able to survive.
So, the model fits the neat way of working quite well. But I cannot use NEAT or any other libraries, so I need to write that code by myself using maths.
Is this possible? And if it is too hard for a beginner, are there any source to learn from or other examples to look up to? | 2019/03/02 | [
"https://stats.stackexchange.com/questions/395216",
"https://stats.stackexchange.com",
"https://stats.stackexchange.com/users/239612/"
] | This seems like a fun project. In games though, there's less use of AI approaches than explicitly coded behavior trees or scripted behavior, if only because AIs are less tweakable in terms of matching player skills.
It's not impossible to do, so try it out. After that, try out the reinforcement learning algorithms. | NEAT was my first approach to the world of Neural Networks.
I was like you, not understanding what was going on or what to do. I coded my first NEAT code in Javascript. A couple of months ago I wrote it in Kotlin and finally I decided to move to Python.
As the paper is not very specific in some important details, each library has the author's interpretation of NEAT. I am writing currently my own algorithm based on it, (like this guy also did): <https://towardsdatascience.com/neuro-evolution-on-steroids-82bd14ddc2f6>
The most important part is that you understand how the math works. My first NEAT algorithm on javascript took me around one month, between literature, understanding and finding answers for not very detailed points of the text.
My second implementation took me around 2 weeks, and I moved everything to Python in around 3 days.
So, I recommend you to read the paper and go in depth about how neural networks work. The type of nets that pure NEAT generates have arbitrary topology, which you can't activate in one timestep, but you need multiple activations to take them to the end.
Check also the NEAT users page: <https://www.cs.ucf.edu/~kstanley/neat.html>
It has lots of answers of unanswered questions of the paper.
And I totally recommend you to do it. As I did my whole implementation from scratch (including neural networks) I can be pretty much flexible about what I want to do. |
239,025 | In my company, we have had a policy of tagging every release. Someone new joined, and he suggested that instead of formally using a Tag, we could just leave a comment for the release build when it is checked in. I like using a Tag, but, obviously, we can also get to the source code for a build also by looking for the comment. The only advantage I see is that because our product spans multiple technologies, we can group the source code for both in the same directory with a folder for each. **Is there some other advantage of tagging releases that I'm missing?** BTW, we are using SVN. | 2014/05/14 | [
"https://softwareengineering.stackexchange.com/questions/239025",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104647/"
] | A tag in subversion is technically the same as a branch. It is only convention that keeps you from modifying a tag after it was created.
Last year I had a situation where we were very happy that we use tags in subversion.
We had created a release and tagged that release. In parallel to the acceptance tests on the release, normal development continued on the trunk of the repository.
The problem was that late in the acceptance tests, a critical issue was found that absolutely had to be solved, but the new stuff that was being developed could absolutely not be included in the release, because it was far from being stable enough.
We resolved that finally by making use of the fact that under the hood a tag is the same as a branch, so we made the change directly on the tag. If we had used check-in comments to 'tag' our releases, that would not have been as easy to do.
Besides that, if your project consists of multiple projects that evolve at a different rate but are always released together, then a subversion tag ensures that you have a correct snapshot of all the projects at the time of the release, even if some of them haven't changed since the last release. If you use check-in comments to mark a release, you must make a check-in on each project, even if nothing has changed. | Some customer who cannot upgrade to a newer version ask you for support for version x.y.z. A tag with that release will help you identify the code you need to inspect. Ask the new guy to search the release using commit comments. Please, do it! |
239,025 | In my company, we have had a policy of tagging every release. Someone new joined, and he suggested that instead of formally using a Tag, we could just leave a comment for the release build when it is checked in. I like using a Tag, but, obviously, we can also get to the source code for a build also by looking for the comment. The only advantage I see is that because our product spans multiple technologies, we can group the source code for both in the same directory with a folder for each. **Is there some other advantage of tagging releases that I'm missing?** BTW, we are using SVN. | 2014/05/14 | [
"https://softwareengineering.stackexchange.com/questions/239025",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104647/"
] | Some customer who cannot upgrade to a newer version ask you for support for version x.y.z. A tag with that release will help you identify the code you need to inspect. Ask the new guy to search the release using commit comments. Please, do it! | Yes, you can use the revision number to uniquely identify a snapshot in time.
But... where do you record which revnum matches which release? Will you keep a spreadsheet that says "release 4.2.1" is Revnum 18345? Not recommended.
However, creating a Tag 'branch' does exactly this without the need for spreadsheets or external tooling - if you remember a branch in SVN is just a copy of the repository state (like a symlink) then you realise that a Tag is not much more than a pointer to the revision you want to remember. You get all the benefit of a snapshot in time, but with the advantage of being able to name it something meaningful.
You also get other benefits, as its a branch, you can make patch fixes to it. Code made to trunk can be merged into it when necessary. You can create a new branch from that branch so you can make a forked product if you need to. You can switch your working copy to the Tagged release with a single command. All of this can also be done by recording the revnum, but its much easier to use a Tag, and as it doesn't cost anything you might as well go with the easy option. |
239,025 | In my company, we have had a policy of tagging every release. Someone new joined, and he suggested that instead of formally using a Tag, we could just leave a comment for the release build when it is checked in. I like using a Tag, but, obviously, we can also get to the source code for a build also by looking for the comment. The only advantage I see is that because our product spans multiple technologies, we can group the source code for both in the same directory with a folder for each. **Is there some other advantage of tagging releases that I'm missing?** BTW, we are using SVN. | 2014/05/14 | [
"https://softwareengineering.stackexchange.com/questions/239025",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104647/"
] | Some customer who cannot upgrade to a newer version ask you for support for version x.y.z. A tag with that release will help you identify the code you need to inspect. Ask the new guy to search the release using commit comments. Please, do it! | Another reason to use tags instead of revision numbers to track what you released is it's easier to keep links/references to tags than to revisions of trunk (or branches). References to particular paths at some old revision can break if you reorganize your trunk (or branch) folder layout in the future. Tags don't change (by convention), so they don't have that problem. |
239,025 | In my company, we have had a policy of tagging every release. Someone new joined, and he suggested that instead of formally using a Tag, we could just leave a comment for the release build when it is checked in. I like using a Tag, but, obviously, we can also get to the source code for a build also by looking for the comment. The only advantage I see is that because our product spans multiple technologies, we can group the source code for both in the same directory with a folder for each. **Is there some other advantage of tagging releases that I'm missing?** BTW, we are using SVN. | 2014/05/14 | [
"https://softwareengineering.stackexchange.com/questions/239025",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104647/"
] | A tag in subversion is technically the same as a branch. It is only convention that keeps you from modifying a tag after it was created.
Last year I had a situation where we were very happy that we use tags in subversion.
We had created a release and tagged that release. In parallel to the acceptance tests on the release, normal development continued on the trunk of the repository.
The problem was that late in the acceptance tests, a critical issue was found that absolutely had to be solved, but the new stuff that was being developed could absolutely not be included in the release, because it was far from being stable enough.
We resolved that finally by making use of the fact that under the hood a tag is the same as a branch, so we made the change directly on the tag. If we had used check-in comments to 'tag' our releases, that would not have been as easy to do.
Besides that, if your project consists of multiple projects that evolve at a different rate but are always released together, then a subversion tag ensures that you have a correct snapshot of all the projects at the time of the release, even if some of them haven't changed since the last release. If you use check-in comments to mark a release, you must make a check-in on each project, even if nothing has changed. | A tag is precisely made to be able to get the exact snapshot of the sources at the moment you created it. It is 1000000 times more convenient than looking at the submit comments....especially if your release requiered several commits (or more).
Furthermore, the case where a important bug is dicovered in acceptance or in **production** while the development is ongoing and not stable enough is quite common!
In that case you have to create a branch. As others mentioned, a tag is beyond the scene a branch in SVN so you are saved in that case but tagging can also save your life with other tools because many tools allow you to create a branch from tag (CVS, TFS and certainly others).
Just try it with comments only! |
239,025 | In my company, we have had a policy of tagging every release. Someone new joined, and he suggested that instead of formally using a Tag, we could just leave a comment for the release build when it is checked in. I like using a Tag, but, obviously, we can also get to the source code for a build also by looking for the comment. The only advantage I see is that because our product spans multiple technologies, we can group the source code for both in the same directory with a folder for each. **Is there some other advantage of tagging releases that I'm missing?** BTW, we are using SVN. | 2014/05/14 | [
"https://softwareengineering.stackexchange.com/questions/239025",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104647/"
] | A tag in subversion is technically the same as a branch. It is only convention that keeps you from modifying a tag after it was created.
Last year I had a situation where we were very happy that we use tags in subversion.
We had created a release and tagged that release. In parallel to the acceptance tests on the release, normal development continued on the trunk of the repository.
The problem was that late in the acceptance tests, a critical issue was found that absolutely had to be solved, but the new stuff that was being developed could absolutely not be included in the release, because it was far from being stable enough.
We resolved that finally by making use of the fact that under the hood a tag is the same as a branch, so we made the change directly on the tag. If we had used check-in comments to 'tag' our releases, that would not have been as easy to do.
Besides that, if your project consists of multiple projects that evolve at a different rate but are always released together, then a subversion tag ensures that you have a correct snapshot of all the projects at the time of the release, even if some of them haven't changed since the last release. If you use check-in comments to mark a release, you must make a check-in on each project, even if nothing has changed. | Yes, you can use the revision number to uniquely identify a snapshot in time.
But... where do you record which revnum matches which release? Will you keep a spreadsheet that says "release 4.2.1" is Revnum 18345? Not recommended.
However, creating a Tag 'branch' does exactly this without the need for spreadsheets or external tooling - if you remember a branch in SVN is just a copy of the repository state (like a symlink) then you realise that a Tag is not much more than a pointer to the revision you want to remember. You get all the benefit of a snapshot in time, but with the advantage of being able to name it something meaningful.
You also get other benefits, as its a branch, you can make patch fixes to it. Code made to trunk can be merged into it when necessary. You can create a new branch from that branch so you can make a forked product if you need to. You can switch your working copy to the Tagged release with a single command. All of this can also be done by recording the revnum, but its much easier to use a Tag, and as it doesn't cost anything you might as well go with the easy option. |
239,025 | In my company, we have had a policy of tagging every release. Someone new joined, and he suggested that instead of formally using a Tag, we could just leave a comment for the release build when it is checked in. I like using a Tag, but, obviously, we can also get to the source code for a build also by looking for the comment. The only advantage I see is that because our product spans multiple technologies, we can group the source code for both in the same directory with a folder for each. **Is there some other advantage of tagging releases that I'm missing?** BTW, we are using SVN. | 2014/05/14 | [
"https://softwareengineering.stackexchange.com/questions/239025",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104647/"
] | A tag in subversion is technically the same as a branch. It is only convention that keeps you from modifying a tag after it was created.
Last year I had a situation where we were very happy that we use tags in subversion.
We had created a release and tagged that release. In parallel to the acceptance tests on the release, normal development continued on the trunk of the repository.
The problem was that late in the acceptance tests, a critical issue was found that absolutely had to be solved, but the new stuff that was being developed could absolutely not be included in the release, because it was far from being stable enough.
We resolved that finally by making use of the fact that under the hood a tag is the same as a branch, so we made the change directly on the tag. If we had used check-in comments to 'tag' our releases, that would not have been as easy to do.
Besides that, if your project consists of multiple projects that evolve at a different rate but are always released together, then a subversion tag ensures that you have a correct snapshot of all the projects at the time of the release, even if some of them haven't changed since the last release. If you use check-in comments to mark a release, you must make a check-in on each project, even if nothing has changed. | Another reason to use tags instead of revision numbers to track what you released is it's easier to keep links/references to tags than to revisions of trunk (or branches). References to particular paths at some old revision can break if you reorganize your trunk (or branch) folder layout in the future. Tags don't change (by convention), so they don't have that problem. |
239,025 | In my company, we have had a policy of tagging every release. Someone new joined, and he suggested that instead of formally using a Tag, we could just leave a comment for the release build when it is checked in. I like using a Tag, but, obviously, we can also get to the source code for a build also by looking for the comment. The only advantage I see is that because our product spans multiple technologies, we can group the source code for both in the same directory with a folder for each. **Is there some other advantage of tagging releases that I'm missing?** BTW, we are using SVN. | 2014/05/14 | [
"https://softwareengineering.stackexchange.com/questions/239025",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104647/"
] | A tag is precisely made to be able to get the exact snapshot of the sources at the moment you created it. It is 1000000 times more convenient than looking at the submit comments....especially if your release requiered several commits (or more).
Furthermore, the case where a important bug is dicovered in acceptance or in **production** while the development is ongoing and not stable enough is quite common!
In that case you have to create a branch. As others mentioned, a tag is beyond the scene a branch in SVN so you are saved in that case but tagging can also save your life with other tools because many tools allow you to create a branch from tag (CVS, TFS and certainly others).
Just try it with comments only! | Yes, you can use the revision number to uniquely identify a snapshot in time.
But... where do you record which revnum matches which release? Will you keep a spreadsheet that says "release 4.2.1" is Revnum 18345? Not recommended.
However, creating a Tag 'branch' does exactly this without the need for spreadsheets or external tooling - if you remember a branch in SVN is just a copy of the repository state (like a symlink) then you realise that a Tag is not much more than a pointer to the revision you want to remember. You get all the benefit of a snapshot in time, but with the advantage of being able to name it something meaningful.
You also get other benefits, as its a branch, you can make patch fixes to it. Code made to trunk can be merged into it when necessary. You can create a new branch from that branch so you can make a forked product if you need to. You can switch your working copy to the Tagged release with a single command. All of this can also be done by recording the revnum, but its much easier to use a Tag, and as it doesn't cost anything you might as well go with the easy option. |
239,025 | In my company, we have had a policy of tagging every release. Someone new joined, and he suggested that instead of formally using a Tag, we could just leave a comment for the release build when it is checked in. I like using a Tag, but, obviously, we can also get to the source code for a build also by looking for the comment. The only advantage I see is that because our product spans multiple technologies, we can group the source code for both in the same directory with a folder for each. **Is there some other advantage of tagging releases that I'm missing?** BTW, we are using SVN. | 2014/05/14 | [
"https://softwareengineering.stackexchange.com/questions/239025",
"https://softwareengineering.stackexchange.com",
"https://softwareengineering.stackexchange.com/users/104647/"
] | A tag is precisely made to be able to get the exact snapshot of the sources at the moment you created it. It is 1000000 times more convenient than looking at the submit comments....especially if your release requiered several commits (or more).
Furthermore, the case where a important bug is dicovered in acceptance or in **production** while the development is ongoing and not stable enough is quite common!
In that case you have to create a branch. As others mentioned, a tag is beyond the scene a branch in SVN so you are saved in that case but tagging can also save your life with other tools because many tools allow you to create a branch from tag (CVS, TFS and certainly others).
Just try it with comments only! | Another reason to use tags instead of revision numbers to track what you released is it's easier to keep links/references to tags than to revisions of trunk (or branches). References to particular paths at some old revision can break if you reorganize your trunk (or branch) folder layout in the future. Tags don't change (by convention), so they don't have that problem. |
297,951 | I am wondering if anyone might have a suggestion about how to request to be addressed by a personal title and one's surname. For example, I prefer to be addressed as, "Mr. Redgate," but I do not wish to come across as rude. I was taught that it was rude to address someone by their Christian name unless that person has given you permission to address them as such; we were admonished for being too familiar.
I am not fond of most people calling me by my Christian name and especially the abbreviated, "Joe," "Jo Jo" or "Joey." Such familiarity, especially by people with whom I am unfamiliar, is quite offensive to me. What is frustrating is that I know that if I politely request that they refrain from such addresses, I am the one who is thought to be rude.
Does anyone have any suggestions? | 2016/01/06 | [
"https://english.stackexchange.com/questions/297951",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/154048/"
] | No, the word *both* can't be used in this way. *Both* only ever refers to two things, never three. You don't need to use anything before the list. the fact that you list all three things and follow it with the third-person plural conjugation of the verb *utilize* indicates that all three items listed constitute the subject. However, if for whatever reason you want to use something like *both* that you could use for three things, then write it as follows:
>
> All three, method A, method B and proposed method C, utilize ID
> information, which makes these methods depend on number size.
>
>
>
-or-
>
> Method A, method B and proposed method C utilize ID information, which
> makes all three methods depend on number size.
>
>
>
-or-
>
> Method A, method B and proposed method C all utilize ID information,
> which makes them depend on number size.
>
>
>
Be sure to note the correction to the conjugation of *depends* to *depend*. | >
> **All** of method A, method B and [the] proposed method utilize ID information, which makes these methods [dependent] on number size.
>
>
>
**All** is the word you are looking for, and has the advantage that it can be used for four or more methods. |
297,951 | I am wondering if anyone might have a suggestion about how to request to be addressed by a personal title and one's surname. For example, I prefer to be addressed as, "Mr. Redgate," but I do not wish to come across as rude. I was taught that it was rude to address someone by their Christian name unless that person has given you permission to address them as such; we were admonished for being too familiar.
I am not fond of most people calling me by my Christian name and especially the abbreviated, "Joe," "Jo Jo" or "Joey." Such familiarity, especially by people with whom I am unfamiliar, is quite offensive to me. What is frustrating is that I know that if I politely request that they refrain from such addresses, I am the one who is thought to be rude.
Does anyone have any suggestions? | 2016/01/06 | [
"https://english.stackexchange.com/questions/297951",
"https://english.stackexchange.com",
"https://english.stackexchange.com/users/154048/"
] | No, the word *both* can't be used in this way. *Both* only ever refers to two things, never three. You don't need to use anything before the list. the fact that you list all three things and follow it with the third-person plural conjugation of the verb *utilize* indicates that all three items listed constitute the subject. However, if for whatever reason you want to use something like *both* that you could use for three things, then write it as follows:
>
> All three, method A, method B and proposed method C, utilize ID
> information, which makes these methods depend on number size.
>
>
>
-or-
>
> Method A, method B and proposed method C utilize ID information, which
> makes all three methods depend on number size.
>
>
>
-or-
>
> Method A, method B and proposed method C all utilize ID information,
> which makes them depend on number size.
>
>
>
Be sure to note the correction to the conjugation of *depends* to *depend*. | Three things happened at once; a, b and c
Three different things happened; a, b, then c
Three conflicting things happened, a, b but not c |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | You can ask for anything you want, but you will not get a refund. The terms and condition of the site where you purchased it most likely clearly stated that it wasn't an option.
One example from Taylor & Francis:
>
> The content in this site is provided "as is" and without warranties of any kind either express or implied.
>
>
> Taylor & Francis Group Ltd do not warrant or make any representations regarding the use or the results of the use of the content in this site in terms of their correctness, accuracy, reliability, or otherwise.
>
>
>
And another piece of sound advice:
>
> If you do not agree to these terms, please do not use this site.
>
>
>
More generally, the money you pay for the article is strictly for its publishing, the actual research that resulted in a "major flaw" was paid via other channels, on which it's very unlikely that you'll have any direct influence. The people making the original claim about the content of an article, and taking responsibility for it, are *the authors* not the publisher to which you paid the fee.
If you witness that a given journal has consistently low acceptance standards, make sure to notify your institution's library, they might consider resigning subscription if they gather enough similar complaints.
Sadly, for the occasional 20 bucks you consider wasted for that article (I'm sure this is purely fictional, there are many ways of getting subscription journal's content without paying for it) there are 10 unscrupulous scholars, somewhere who use 3000$ of your tax money to publish complete rubbish in an open access journal. And here the perspective of a refund is nonexistent. | The publisher does not guarantee that the article has no major flaw. Indeed, for all they know, the reason why you requested access to the article in the first place was to refute it. Or to check other people's criticism of it.
Also, consider how many articles there are that are wrong yet of great historical interest. One example that pops into mind is the papers Einstein published before November 1915, containing his "work in progress" on general relativity, including some blatantly flawed thoughts.
So no, I do not believe you are entitled to a refund. You certainly don't have a legal basis, but I don't believe you have a moral basis either.
I can, however, imagine a scenario in which you might be legally entitled to a refund: if the article in question was based on fraudulent research, and the publisher was complicit in the fraud (e.g., the paper remains available for a fee even after it has been demonstrated unambiguously that it represents fraudulent research). Respectable publishers retract such papers. Other publishers... well, good luck with them. |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | Of course you can request one - just send an email. You'll brighten up the publisher's office for the afternoon, and they'll be chuckling all the way home.
So just as long as you don't seriously expect to get your money back, you'll be fine. When you paid your fee, you were paying for access to read the paper. As long as that access was provided, then the publisher has met their side of the bargain. Peer review is not a guarantee of correctness. It's a first-level junk filter, nothing more.
And on top of you getting what you've paid for, you've got the additional bonus that you've now got a new paper that you can write, that's practically already written itself; the paper where you take apart your bought paper's argument. Magnanimously, the publisher won't require you to pay extra for this bonus - you got it thrown in for free. | You can ask for anything you want, but you will not get a refund. The terms and condition of the site where you purchased it most likely clearly stated that it wasn't an option.
One example from Taylor & Francis:
>
> The content in this site is provided "as is" and without warranties of any kind either express or implied.
>
>
> Taylor & Francis Group Ltd do not warrant or make any representations regarding the use or the results of the use of the content in this site in terms of their correctness, accuracy, reliability, or otherwise.
>
>
>
And another piece of sound advice:
>
> If you do not agree to these terms, please do not use this site.
>
>
>
More generally, the money you pay for the article is strictly for its publishing, the actual research that resulted in a "major flaw" was paid via other channels, on which it's very unlikely that you'll have any direct influence. The people making the original claim about the content of an article, and taking responsibility for it, are *the authors* not the publisher to which you paid the fee.
If you witness that a given journal has consistently low acceptance standards, make sure to notify your institution's library, they might consider resigning subscription if they gather enough similar complaints.
Sadly, for the occasional 20 bucks you consider wasted for that article (I'm sure this is purely fictional, there are many ways of getting subscription journal's content without paying for it) there are 10 unscrupulous scholars, somewhere who use 3000$ of your tax money to publish complete rubbish in an open access journal. And here the perspective of a refund is nonexistent. |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | There is a case where I think you might have a very strong moral claim even if not a legal one: if the paper is retracted, there is no question that you ought to be able to obtain a refund.
**Addendum** One argument contrariwise: The last science needs is any further disincentive for publishers to retract papers. Maybe better for the enterprise as a whole to have a few readers get cheated than to have fraudulent and otherwise untrustworthy papers remain in the literature. | To be successful in a request for a refund, either the publisher would have to be remarkably generous, or they would need to conclude that it is in their best interest. I'm skeptical that appeal to threatened "public hue and cry" would persuade them, since academic publishers are generally immune to negative publicity. A potentially more powerful motivating force would be legal pressure, for which I see two bases. One would be fraud, where the publisher knowingly represented falsehoods as truth. It would be challenging to establish fraud. The second is via warranty of merchantability (in the US enshrined in law via the Uniform Commercial Code article 2). In some cases, e.g. Taylor & Francis (following the lead of every known software producer), publications are offered as-is, in which case you have no option. Any product without an as-is disclaimer carries a warranty, to the effect that if the seller knows (or should know) that the item is used for a particular purpose, then the item is fit for that purpose. This is why one can sue a company for negligence, if they sell something as fit for a purpose when it is not.
In order to make any traction with a threat for violating the implied warranty of merchantability, you would have almost certainly have to enlist the aid of lawyers willing to help you pursue the matter. The two main things that you would have to objectively establish is that the article has a known purpose, and that the article actually is not fit for that purpose. I don't believe that you would have to establish that the publisher was aware of the defect (I'd like to be more assertive about that, but that's what lawyers do).
If you just email them asking for a refund, they will probably say that they don't make any guarantees. However, if your attorney uses suitable language, they would probably reply that they have a stated as-is policy (you're out of luck), or, that there is no way they could know of the mentioned purpose, or that the article is in fact fit for that purpose. Since "merchantability" isn't defined under the law, courts would generally compare the item in question against comparable products. The reason is that no product can be absolutely flawless, and a claimed based on merchantability would have to show that the product was egregiously defective, not just less than satisfactory.
That all said, you did not actually purchase "the article", you purchased a license to copy the article in a particular manner, for which reason it is not clear that UCC article 2 is applicable. |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | There is a case where I think you might have a very strong moral claim even if not a legal one: if the paper is retracted, there is no question that you ought to be able to obtain a refund.
**Addendum** One argument contrariwise: The last science needs is any further disincentive for publishers to retract papers. Maybe better for the enterprise as a whole to have a few readers get cheated than to have fraudulent and otherwise untrustworthy papers remain in the literature. | If you are just looking to get your money back, then I am afraid it is not worth an effort; you probably will spend more on the telephone calls than they charged you for the article.
However, it could be nice to set a precedent like this: to request a refund and eventually to sue a lazy publisher, who do not bother to introduce a proper level of scrutiny in their peer review process, and instead charge the authors to publish some bogus papers and then charge the readers to access them. I have no idea whether or not such a case can win (and I guess it depends on jurisdictions). The question just adds to the bigger question of very complicated relations between academic publishers and academia. |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | Of course you can request one - just send an email. You'll brighten up the publisher's office for the afternoon, and they'll be chuckling all the way home.
So just as long as you don't seriously expect to get your money back, you'll be fine. When you paid your fee, you were paying for access to read the paper. As long as that access was provided, then the publisher has met their side of the bargain. Peer review is not a guarantee of correctness. It's a first-level junk filter, nothing more.
And on top of you getting what you've paid for, you've got the additional bonus that you've now got a new paper that you can write, that's practically already written itself; the paper where you take apart your bought paper's argument. Magnanimously, the publisher won't require you to pay extra for this bonus - you got it thrown in for free. | There's only a few narrow reasons you might demand a refund in this case: first, if the download/manuscript was somehow damaged or malformed, e.g. pages missing, or somehow "broken"; secondly, if the precis you used to make the purchase decision described something fundamentally different than what the paper delivered; third, if there was something fraudulent about the paper.
Being "incorrect" or "false" is different than being "fraudulent." |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | The publisher does not guarantee that the article has no major flaw. Indeed, for all they know, the reason why you requested access to the article in the first place was to refute it. Or to check other people's criticism of it.
Also, consider how many articles there are that are wrong yet of great historical interest. One example that pops into mind is the papers Einstein published before November 1915, containing his "work in progress" on general relativity, including some blatantly flawed thoughts.
So no, I do not believe you are entitled to a refund. You certainly don't have a legal basis, but I don't believe you have a moral basis either.
I can, however, imagine a scenario in which you might be legally entitled to a refund: if the article in question was based on fraudulent research, and the publisher was complicit in the fraud (e.g., the paper remains available for a fee even after it has been demonstrated unambiguously that it represents fraudulent research). Respectable publishers retract such papers. Other publishers... well, good luck with them. | If you are just looking to get your money back, then I am afraid it is not worth an effort; you probably will spend more on the telephone calls than they charged you for the article.
However, it could be nice to set a precedent like this: to request a refund and eventually to sue a lazy publisher, who do not bother to introduce a proper level of scrutiny in their peer review process, and instead charge the authors to publish some bogus papers and then charge the readers to access them. I have no idea whether or not such a case can win (and I guess it depends on jurisdictions). The question just adds to the bigger question of very complicated relations between academic publishers and academia. |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | There is a case where I think you might have a very strong moral claim even if not a legal one: if the paper is retracted, there is no question that you ought to be able to obtain a refund.
**Addendum** One argument contrariwise: The last science needs is any further disincentive for publishers to retract papers. Maybe better for the enterprise as a whole to have a few readers get cheated than to have fraudulent and otherwise untrustworthy papers remain in the literature. | There's only a few narrow reasons you might demand a refund in this case: first, if the download/manuscript was somehow damaged or malformed, e.g. pages missing, or somehow "broken"; secondly, if the precis you used to make the purchase decision described something fundamentally different than what the paper delivered; third, if there was something fraudulent about the paper.
Being "incorrect" or "false" is different than being "fraudulent." |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | The publisher does not guarantee that the article has no major flaw. Indeed, for all they know, the reason why you requested access to the article in the first place was to refute it. Or to check other people's criticism of it.
Also, consider how many articles there are that are wrong yet of great historical interest. One example that pops into mind is the papers Einstein published before November 1915, containing his "work in progress" on general relativity, including some blatantly flawed thoughts.
So no, I do not believe you are entitled to a refund. You certainly don't have a legal basis, but I don't believe you have a moral basis either.
I can, however, imagine a scenario in which you might be legally entitled to a refund: if the article in question was based on fraudulent research, and the publisher was complicit in the fraud (e.g., the paper remains available for a fee even after it has been demonstrated unambiguously that it represents fraudulent research). Respectable publishers retract such papers. Other publishers... well, good luck with them. | There is a case where I think you might have a very strong moral claim even if not a legal one: if the paper is retracted, there is no question that you ought to be able to obtain a refund.
**Addendum** One argument contrariwise: The last science needs is any further disincentive for publishers to retract papers. Maybe better for the enterprise as a whole to have a few readers get cheated than to have fraudulent and otherwise untrustworthy papers remain in the literature. |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | Of course you can request one - just send an email. You'll brighten up the publisher's office for the afternoon, and they'll be chuckling all the way home.
So just as long as you don't seriously expect to get your money back, you'll be fine. When you paid your fee, you were paying for access to read the paper. As long as that access was provided, then the publisher has met their side of the bargain. Peer review is not a guarantee of correctness. It's a first-level junk filter, nothing more.
And on top of you getting what you've paid for, you've got the additional bonus that you've now got a new paper that you can write, that's practically already written itself; the paper where you take apart your bought paper's argument. Magnanimously, the publisher won't require you to pay extra for this bonus - you got it thrown in for free. | The publisher does not guarantee that the article has no major flaw. Indeed, for all they know, the reason why you requested access to the article in the first place was to refute it. Or to check other people's criticism of it.
Also, consider how many articles there are that are wrong yet of great historical interest. One example that pops into mind is the papers Einstein published before November 1915, containing his "work in progress" on general relativity, including some blatantly flawed thoughts.
So no, I do not believe you are entitled to a refund. You certainly don't have a legal basis, but I don't believe you have a moral basis either.
I can, however, imagine a scenario in which you might be legally entitled to a refund: if the article in question was based on fraudulent research, and the publisher was complicit in the fraud (e.g., the paper remains available for a fee even after it has been demonstrated unambiguously that it represents fraudulent research). Respectable publishers retract such papers. Other publishers... well, good luck with them. |
57,937 | Is it possible to get a refund from a publisher if I bought an article that contains a major flaw (i.e.,one that invalidates the main results or the main conclusions)? Assume the article was bought through one of the main academic publication's paywall. | 2015/11/10 | [
"https://academia.stackexchange.com/questions/57937",
"https://academia.stackexchange.com",
"https://academia.stackexchange.com/users/452/"
] | The publisher does not guarantee that the article has no major flaw. Indeed, for all they know, the reason why you requested access to the article in the first place was to refute it. Or to check other people's criticism of it.
Also, consider how many articles there are that are wrong yet of great historical interest. One example that pops into mind is the papers Einstein published before November 1915, containing his "work in progress" on general relativity, including some blatantly flawed thoughts.
So no, I do not believe you are entitled to a refund. You certainly don't have a legal basis, but I don't believe you have a moral basis either.
I can, however, imagine a scenario in which you might be legally entitled to a refund: if the article in question was based on fraudulent research, and the publisher was complicit in the fraud (e.g., the paper remains available for a fee even after it has been demonstrated unambiguously that it represents fraudulent research). Respectable publishers retract such papers. Other publishers... well, good luck with them. | There's only a few narrow reasons you might demand a refund in this case: first, if the download/manuscript was somehow damaged or malformed, e.g. pages missing, or somehow "broken"; secondly, if the precis you used to make the purchase decision described something fundamentally different than what the paper delivered; third, if there was something fraudulent about the paper.
Being "incorrect" or "false" is different than being "fraudulent." |
254,269 | What additional privileges does the root user have over a standard user in Linux? | 2016/01/09 | [
"https://unix.stackexchange.com/questions/254269",
"https://unix.stackexchange.com",
"https://unix.stackexchange.com/users/150799/"
] | The root user can do pretty much anything that the hardware allows. The root user can write directly to hard drives without going through the filesystem. Root can modify the kernel via modules. The root user can also circumvent any security policy of the system software: he can change ownership of any files, set up privileged ports, write to privileged filesystem locations, gain extra scheduling priority levels, etc. The root user can also spy on any other user in the system.
Regular users can generally only manipulate their own processes and their own filesystem subtrees. They tend to be forbidden from manipulating the system's hardware, security policies, and from meddling with other users' files and processes. | root is the system administrator, and they can do whatever they want to the system, which can lead to data corruption if the account is not used wisely. Since it appears you are new to Linux, I would recommend you not use root until you get more experience with Linux. To access an administrator/root command prompt from a standard users command prompt, type `su` (I believe most distros support this) and then hit enter.
*Beware when using root, as you can really mess up your computer.* |
3,772,916 | I know this is not a very technical question, but it's for all technical people, that's why I ask it here. Here is my question:
Can someone help me understand the current and future of learning LISP? One of my papers in university uses LISP for a project (it's a big project - may be two semester long), and I am not able to decide whether I should put lots of effort into learning LISP if there is no future in LISP, or should I just learn as much as needed for the assignments and do some other project which doesn't need any LISP. I know a little bit of basic LISP. Please help me. | 2010/09/22 | [
"https://Stackoverflow.com/questions/3772916",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/154070/"
] | I believe there is a lot of value in LISP and currently we see a kind of Lisp renaissance, with new languages like clojure. Even Python and Ruby are very lispy under the skin.
Also the concepts learned in LISP often transfer over to other languages and will make you a better developer whatever language you use on the day job. | ### It has no commercial future but learn it anyway
You aren't fully educated in computer science until you know Lisp.
---
If Lisp was going to catch on it would have done so, you know, in the last 50 years or so. You can disregard the people saying that Lisp implementation #127 is going to finally catch on.
Still, it is so unique and powerful that it should be well worth your time to understand it. |
3,772,916 | I know this is not a very technical question, but it's for all technical people, that's why I ask it here. Here is my question:
Can someone help me understand the current and future of learning LISP? One of my papers in university uses LISP for a project (it's a big project - may be two semester long), and I am not able to decide whether I should put lots of effort into learning LISP if there is no future in LISP, or should I just learn as much as needed for the assignments and do some other project which doesn't need any LISP. I know a little bit of basic LISP. Please help me. | 2010/09/22 | [
"https://Stackoverflow.com/questions/3772916",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/154070/"
] | If you have a real interest in software development, you should learn Lisp and other programming languages.
Ruby, Python and Perl are distant relatives of Lisp. A bit nearer is Javascript - which is basically a primitive Lisp with a strange non-programmable syntax.
The core of Scheme is relatively clean and quite powerful. Teaches basic concepts.
Common Lisp is a powerful language which has all kinds of 'exotic' extensions. You can experience multi-paradigm programming in a single language.
Clojure is a newer Lisp which breaks with the Lisp tradition in multiple ways, but offers an interesting blend of a functional language and concurrency.
All three Lisp dialects offer meta-linguistic abstraction capabilities that few languages offer in such an elegant way (Prolog would be another interesting language that has similar capabilities).
Experiencing that code is data and data can be code will change your view on programming forever. | I believe there is a lot of value in LISP and currently we see a kind of Lisp renaissance, with new languages like clojure. Even Python and Ruby are very lispy under the skin.
Also the concepts learned in LISP often transfer over to other languages and will make you a better developer whatever language you use on the day job. |
3,772,916 | I know this is not a very technical question, but it's for all technical people, that's why I ask it here. Here is my question:
Can someone help me understand the current and future of learning LISP? One of my papers in university uses LISP for a project (it's a big project - may be two semester long), and I am not able to decide whether I should put lots of effort into learning LISP if there is no future in LISP, or should I just learn as much as needed for the assignments and do some other project which doesn't need any LISP. I know a little bit of basic LISP. Please help me. | 2010/09/22 | [
"https://Stackoverflow.com/questions/3772916",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/154070/"
] | Lisp is one of those languages that really changes the way you think about programming. If by value you mean marketability, it has very little value. If you mean value as in what it gives you as a developer, I would say that it is quite a bit higher. | Some of the features that we take for granted in new languages had their origins in Lisp. ([This article](http://www.paulgraham.com/diff.html) has more information on this). Languages [continue to borrow](http://blog.vmathew.in/invokedynamic) ideas from Lisp. Lisp's biggest advantage is its ability to represent *code as data and data as code*, which most of the 'popular' languages cannot accommodate because of their convoluted syntax. Lisp remains at the forefront of programming language research, and the next *earth shaking* language will be closer to Lisp than to anything else! So a knowledge of Lisp programming will keep you ahead in the game. |
3,772,916 | I know this is not a very technical question, but it's for all technical people, that's why I ask it here. Here is my question:
Can someone help me understand the current and future of learning LISP? One of my papers in university uses LISP for a project (it's a big project - may be two semester long), and I am not able to decide whether I should put lots of effort into learning LISP if there is no future in LISP, or should I just learn as much as needed for the assignments and do some other project which doesn't need any LISP. I know a little bit of basic LISP. Please help me. | 2010/09/22 | [
"https://Stackoverflow.com/questions/3772916",
"https://Stackoverflow.com",
"https://Stackoverflow.com/users/154070/"
] | If you have a real interest in software development, you should learn Lisp and other programming languages.
Ruby, Python and Perl are distant relatives of Lisp. A bit nearer is Javascript - which is basically a primitive Lisp with a strange non-programmable syntax.
The core of Scheme is relatively clean and quite powerful. Teaches basic concepts.
Common Lisp is a powerful language which has all kinds of 'exotic' extensions. You can experience multi-paradigm programming in a single language.
Clojure is a newer Lisp which breaks with the Lisp tradition in multiple ways, but offers an interesting blend of a functional language and concurrency.
All three Lisp dialects offer meta-linguistic abstraction capabilities that few languages offer in such an elegant way (Prolog would be another interesting language that has similar capabilities).
Experiencing that code is data and data can be code will change your view on programming forever. | Some of the features that we take for granted in new languages had their origins in Lisp. ([This article](http://www.paulgraham.com/diff.html) has more information on this). Languages [continue to borrow](http://blog.vmathew.in/invokedynamic) ideas from Lisp. Lisp's biggest advantage is its ability to represent *code as data and data as code*, which most of the 'popular' languages cannot accommodate because of their convoluted syntax. Lisp remains at the forefront of programming language research, and the next *earth shaking* language will be closer to Lisp than to anything else! So a knowledge of Lisp programming will keep you ahead in the game. |
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